The BuleHero botnet was seen using multiple modules to move laterally on a network and increase the spread of its two payloads, the XMRig miner and the Gh0st remote-access Trojan (RAT).
ZScaler uncovered that the BuleHero botnet derived its name from the domain bulehero[.]in found in its binary. Closer analysis of the malware revealed that BuleHero used Swpuhostd.exe to drop a port scanning tool so the botnet could scan for exposed and vulnerable machines connected to the network. Researchers observed the threat sequentially scanning for IP addresses with ports 80 and 3389 open. It then saved these results into a Results.txt file.
In the samples it analyzed, ZScaler discovered that BuleHero used those port scanning results together with Mimikatz to dump passwords from infected hosts. It then gave those passwords to PsExec and WMIC, tools that helped the malware spread to other machines on the network. At that time, the botnet dropped XMRig miner and Gh0st RAT as its embedded malware payloads.
The Growing Prevalence of Lateral Movement
The BuleHero botnet isn’t the only recently discovered threat known for using lateral movement to spread across a network and infect other machines. At the beginning of December, for instance, IBM X-Force uncovered a new wiper called ZeroCleare that spread to numerous devices on an affected network in an effort to target energy organizations in the Middle East.
Around the same time, SentinelOne revealed that TrickBot had embraced new techniques allowing it to automatically collect network information and move laterally within networks. Also in December, the Microsoft Threat Intelligence Center disclosed its discovery of GALLIUM, a threat group known for using Mimikatz to obtain credentials for the purpose of moving laterally on an affected network.
How to Defend Against the BuleHero Botnet
Security professionals can help their organizations defend against the BuleHero botnet by leveraging user behavior analytics (UBA) to identify patterns that could point to potentially malicious behavior on the network. Companies should also invest in figuring out where their organization’s sensitive data resides, where it comes from and where it’s typically going so that they can monitor for suspicious processes involving that information.
David Bisson is an infosec news junkie and security journalist. He works as Contributing Editor for Graham Cluley Security News and Associate Editor for Trip...