Microsoft warned Linux administrators about a crypto mining malware campaign. Microsoft stated that the threat actor group known as 8220 is updating its techniques and payloads to breach Linux servers to deploy a crypto miner. The Chinese-speaking gang is active since 2017 and is known for Monero-mining activities. The group is named after port 8220, which they prefer to communicate with command-and-control. The 8220 gang is also known as the creator of whatMiner.
Confluence and WebLogic vulnerabilities
Microsoft stated that the new campaign is targeting i686 and x86_64 Linux systems. The gang is mainly exploiting two vulnerabilities to deploy the crypto miner, CVE-2022-26134 found in Confluence and CVE-2019-2725 found in WebLogic. Once they established the initial access, the loader is downloaded from jira[.]letmaker[.]top, which is capable of clearing log files and disabling cloud monitoring and security tools to evade detection.
Then it downloads pwnRig crypto miner version 1.41.0 and an IRC bot to run commands from a C2 server. The loader also uses an IP port scanner tool to find other SSH servers in the network and uses a brute force tool named spirit to propagate. It also scans for SSH keys to move laterally by connecting to known hosts. Microsoft urged users to protect their networks against this threat and stated that Microsoft Defender for Endpoint on Linux detects malicious behaviors and payloads related to this campaign.
We observed notable updates to the long-running malware campaign targeting Linux systems by a group known as the 8220 gang. The updates include the deployment of new versions of a cryptominer and an IRC bot, as well the use of an exploit for a recently disclosed vulnerability.
— Microsoft Security Intelligence (@MsftSecIntel) June 29, 2022
Microsoft’s announcement came shortly after Akamai‘s announcement about the Confluence zero-day vulnerability. Akamai stated that exploitation attempts have settled at around 20,000 per day, down from 100,000. After the disclosure, approximately 6,000 IPs are attempting to exploit the Atlassian vulnerability every day. Akamai said;
« As defenders, we have to be extra vigilant, especially when zero-day attacks pop up. These types of attacks have a massive impact on the community. The effects are much more than headline news, these are real exploits that affect real people, how much time they are spending at work, and how they get their jobs done.
What is particularly concerning is how much of a shift upward this attack type has garnered over the last several weeks. As we have seen with similar vulnerabilities, this CVE-2022-26134 will likely continue to be exploited for at least the next couple of years. Due to the large uptick in the baseline of attacks attempts today, this attack type could potentially become a known TTP, a heavily used tool in an attacker’s arsenal moving forward. »