A menace group probably based mostly in Romania and energetic since at the least 2020 has been behind an energetic cryptojacking marketing campaign focusing on Linux-based machines with a beforehand undocumented SSH brute-forcer written in Golang.
Dubbed “Diicot brute,” the password cracking software is alleged to be distributed by way of a software-as-a-service mannequin, with every menace actor furnishing their very own distinctive API keys to facilitate the intrusions, Bitdefender researchers mentioned in a report printed final week.
Whereas the objective of the marketing campaign is to deploy Monero mining malware by remotely compromising the units by way of brute-force assaults, the researchers related the gang to at the least two DDoS botnets, together with a Demonbot variant referred to as chernobyl and a Perl IRC bot, with the XMRig mining payload hosted on a website named mexalz[.]us since February 2021.
The Romanian cybersecurity expertise firm mentioned it started its investigation into the group’s cyber actions in Might 2021, resulting in the following discovery of the adversary’s assault infrastructure and toolkit.
The group can also be identified for counting on a bag of obfuscation methods that allow them to slide below the radar. To that finish, the Bash scripts are compiled with a shell script compiler (shc), and the assault chain has been discovered to leverage Discord to report the knowledge again to a channel below their management, a way that has turn into increasingly common among malicious actors for command-and-control communications and evade safety.
Utilizing Discord as a knowledge exfiltration platform additionally absolves the necessity for menace actors to host their very own command-and-control server, to not point out enabling help for creating communities centered round shopping for and promoting malware supply code and companies.
“Hackers going after weak SSH credentials shouldn’t be unusual,” the researchers mentioned. “Among the many largest issues in safety are default person names and passwords, or weak credentials hackers can overcome simply with brute power. The tough half shouldn’t be essentially brute-forcing these credentials however doing it in a means that lets attackers go undetected.”