Threat actors are actively exploiting a now-patched, critical security flaw impacting the Atlassian Confluence Data Center and Confluence Server to conduct illicit cryptocurrency mining on susceptible instances.
“The attacks involve threat actors that employ methods such as the deployment of shell scripts and XMRig miners, targeting of SSH endpoints, killing competing crypto mining processes, and maintaining persistence via cron jobs,” Trend Micro researcher Abdelrahman Esmail said.
The security vulnerability exploited is CVE-2023-22527, a maximum severity bug in older versions of Atlassian Confluence Data Center and Confluence Server that could allow unauthenticated attackers to achieve remote code execution. It was addressed by the Australian software company in mid-January 2024.
Trend Micro said it observed a high number of exploitation attempts against the flaw between mid-June and end of July 2024 that leveraged it to drop the XMRig miner on unpatched hosts. At least three different threat actors are said to be behind the malicious activity –
- Launching XMRig miner via an ELF file payload using specially crafted requests
- Using a shell script that first terminates competing cryptojacking campaigns (e.g., Kinsing), deletes all existing cron jobs, uninstalls cloud security tools from Alibaba and Tencent, and gathers system information, before setting up a new cron job that checks for command-and-control (C2) server connectivity every five minutes and launching the miner
“With its continuous exploitation by threat actors, CVE-2023-22527 presents a significant security risk to organizations worldwide,” Esmail said.
“To minimize the risks and threats associated with this vulnerability, administrators should update their versions of Confluence Data Center and Confluence Server to the latest available versions as soon as possible.”