Rewterz Threat Alert – Watchbog – Cryptomining and Lateral Movement

Severity

Medium

Analysis Summary

The Watchbog botnet, which uses the XMR-Stak Monero miner, has been observed being installed onto vulnerable systems by exploiting a Jenkins vulnerability, CVE-2018-1000861, and also attempts to spread laterally, according to a report from Cisco Talos. While the attackers take some small steps, such as using base64 encoding to obfuscate their malicious code, the attacks operate largely in the open. Typical of cryptomining malware, the installation script checks for the presence of other cryptomining tools and, if found, terminates them. The script also obtains configuration data from Pastebin URLs and installs a system-compatible version of the XMR-Stak miner from a Github URL. While the attackers leave a note on infected systems claiming they only wish to mine cryptocurrency, the fact that they attempt to move laterally and infect other systems tends to bely that. The lateral movement is attempted in two ways, the first being to use SSH, querying the systems known_hosts file, and checking for SSH keys which can be used to authenticate to the remote systems. The second is by scanning the victim’s subnet for open Jenkins and Redis ports. If found, an attempt will be made to exploit the system using the CVE-2018-1000861 vulnerability. If exploitation is successful in either of the cases, the process to infect the victim with the Watchbog malware will begin.

Impact

Exposure of sensitive information

Indicators of Compromise

Malware Hash (MD5/SHA1/SH256)

b383d0fdfa5036ccfa5d9c2b43cbfd814bce8778978873057b86678e5295fc61
0b0567c9b45ea0a3ea4267001f0760ccdf2b8224fceaf8979d32fcceb2d6fb7a
3A6271A90D0F6CC8A2D31D45D931E8401F13F7377932BA07D871DC42F252B9CA

Remediation

• Block all threat indicators at your respective controls.
• Always be suspicious about emails sent by unknown senders.
• Never click on the link/attachments sent by unknown senders.