Thousands of Sites Infected With Linux Encryption Ransomware

[Reefa]

Thousands of websites have already been infected with the Linux file-encrypting ransomware dubbed Linux.Encoder1, security firms reported.

When the existence of Linux.Encoder1 came to light earlier this month, Russian antivirus firm Doctor Web reported that the threat had infected tens of machines, but the number has since increased considerably.

Researchers say the ransomware is designed to infect Linux machines set up to host websites by exploiting vulnerabilities in the Magento e-commerce platform and various content management systems (CMSs).

The malware targets the root and home folders, and directories storing websites, web servers, backups and source code. The extent of the damage caused by the threat depends on the type of privileges it can obtain on the targeted system.

Based on a Google search for the ransom note dropped by Linux.Encoder1, Dr. Web determined that approximately 2,000 websites had been affected as of November 12. A similar Google search conducted by SecurityWeek early on Monday showed that the file was present on roughly 2,600 websites.

Bitdefender believes the number of Linux.Encoder1 infections will continue to rise.

“With most web servers running some Linux OS distribution and shared hosting, it’s safe to assume that if one such website if affected, others sharing the same resources could be affected as well, if they not properly isolated from each other,” Liviu Arsene, Senior E-threat Analyst at Bitdefender, told SecurityWeek. “Since the infection method does not involve any form of social engineering – servers are usually compromised via unpatched vulnerabilities – hosting providers are strongly encouraged to update any outdated software (wordpress, plugins, etc.). More websites will be surely be affected in the immediate future.”

This Linux encryption ransomware uses strong encryption to ensure that victims cannot recover their files without paying the one Bitcoin ($380) ransom. The files are encrypted using the AES-128 algorithm with a key generated locally on the infected device. This key is then encrypted with an RSA public key and since the private key needed for decryption is only stored on the attacker’s machine, it should be nearly impossible to recover files.

However, researchers discovered that the AES key can be easily recovered since it’s generated based on a system timestamp obtained at the moment of encryption. This timestamp can be retrieved from the encrypted file, which has allowed antivirus firms to develop tools that can be used to automatically recover files.

Both Bitdefender and Dr. Web have developed such tools, but Dr. Web’s service is only available to the company’s customers.

While files encrypted by early versions of Linux.Encoder1 can be easily recovered, experts have warned that malware authors might fix the current bugs, making files more difficult to decrypt.

securityweek.com

[steven36]

​How to easily defeat Linux Encoder ransomware

You see the would-be cyber-criminals made a fundamental mistake. Their encryption method uses a faulty implementation of Advanced Encryption Standard (AES) to generate the encryption key. Specifically, as the anti-virus company Bitdefender reported, the "AES key is generated locally on the victim's computer. ... rather than generating secure random keys and IVs [initialization vector], the sample would derive these two pieces of information from the libc rand() function seeded with the current system time-stamp at the moment of encryption. This information can be easily retrieved by looking at the file's time-stamp."

Armed with this, it's trivial -- well, for encryption experts -- to find the key you need to restore your files. Since most of you don't know your AES from your Playfair, Bitdefender is offering a free Python 2.7 script to obtain the Linux.Encoder key and IV for your containinated server.

Here's how to use it.

If you can boot your compromised server, download the script, and run it as root . If you can't boot, download and decompress the file to a Linux live USB stick. For this job, I recommend the SystemRescueCD Linux distribution.

Then, mount the encrypted partition using the shell command :

mount /dev/[encrypted_partition]

Generate a list of encrypted files with the following command:

/mnt# sort_files.sh encrypted_partition > sorted_list

Issue a head command to get the first file:

/mnt# head -1 sorted_list

Run the decryption utility to get the encryption seed:

/mnt# python decrypter.py -f [first_file]

Decrypt all the other infected files using the displayed seed:

/mnt# python /tmp/new/decrypter.py -s [time-stamp.] -l sorted_list

Not comfortable with the Linux shell? Get someone who is a Linux expert to help you.

Bitdefender is also, very generously, offering to help users with free support from their web site. Go to the bottom of the page to find the form.

Finally, and always: Update your software always. If everyone had simply done this that alone would have stopped Linux.Encoder in its tracks.

http://www.zdnet.com/article/how-to-fix-linux-encoder-ransomware/

People who got this got it from not doing auto updates on there server . Its about like people who never do windows updates one day something like this is going to happen too you. :ph34r: