ESET security company has discovered a new form of malware that targets Linux devices. Malicious software can give full control of the affected device to hackers, leaving a door open for too many other malicious actions, such as DDoS attacks.
The new malware named Rakos, and is used to attack mobile devices and servers that have an open SSH port. If it finds any port open in the SSH protocol it uses brute force attacks to crack the password.
ESET claims that the creators of Rakos want to infect as many systems as possible to create a botnet which they could use for other malicious attacks such as DDoS attacks or spreading spam.
Initially, attackers scan systems for vulnerabilities by analyzing predefined IPs. We should mention that machines that use very weak passwords are most at risk as brute force attacks take much longer in large codes.
Once the victim's Linux device has been accessed, Rakos launches a local HTTP service available at http: // 127.0.0.1: 61314 for two different purposes.
"The first is a sly way for future versions of the bot to stop various processes regardless of their name by simply asking for the address http://127.0.0.1:61314/et and the second tries to parse a URL query with parameters "ip", "u", "p", requesting the address http://127.0.0.1:61314/ex. The purpose of this / ex HTTP is not yet clear, "according to ESET.
The malware automatically scans the infected system and collects information που στη συνέχεια αποστέλλει σε ένα διακομιστή C&C. Στις πληροφορίες συμπεριλαμβάνονται η διεύθυνση IP, ονόματα χρηστών και κωδικοί πρόσβασης.
A conf locally stored conf makes it possible to access a backdoor for the attacker to access and some other time in the future.
It is important to emphasize that SSH's complex passwords are virtually impossible to break from this malware, and attackers are mostly looking for devices that use weak passwords.
If for some reason your Linux machine is infected, you should log in using SSH/Telnet and search for a procedure called .javaxxx. Make sure it is the one used for spam connections and kill the process.
Read more on ESET's publication.