Lifeboat Foundation

Poorly secured Linux SSH servers are being targeted by bad actors to install port scanners and dictionary attack tools with the goal of targeting other vulnerable servers and co-opting them into a network to carry out cryptocurrency mining and distributed denial-of-service (DDoS) attacks.

“Threat actors can also choose to install only scanners and sell the breached IP and account credentials on the dark web,” the AhnLab Security Emergency Response Center (ASEC) said in a report on Tuesday.

In these attacks, adversaries try to guess a server’s SSH credentials by running through a list of commonly used combinations of usernames and passwords, a technique called dictionary attack.