*Rapid7 Incident Response consultants Noah Hemker, Tyler Starks, and malware analyst Tom Elkins contributed analysis and insight to this blog.*
Rapid7 Incident Response was engaged to investigate an incident involving unauthorized access to two publicly-facing Confluence servers that were the source of multiple malware executions. Rapid7 identified evidence of exploitation for CVE-2023-22527 within available Confluence logs. During the investigation, Rapid7 identified cryptomining software and a Sliver Command and Control (C2) payload on in-scope servers. Sliver is a modular C2 framework that provides adversarial emulation capabilities for red teams; however, it’s also frequently abused by threat actors. The Sliver payload was used to action subsequent threat actor objectives within the environment. Without proper security tooling to monitor system network traffic and firewall communications, this activity would have progressed undetected leading to further compromise.
Rapid7 customers
Rapid7 consistently monitors emergent threats to identify areas for new detection opportunities. The recent appearance of Sliver C2 malware prompted Rapid7 teams to conduct a thorough analysis of the techniques being utilized and the potential risks. Rapid7 InsightIDR has an alert rule Suspicious Web Request - Possible Atlassian Confluence CVE-2023-22527 Exploitation available for all IDR customers to detect the usage of the text-inline.vm consistent with the exploitation of CVE-2023-22527. A vulnerability check is also available to InsightVM and Nexpose customers. A Velociraptor artifact to hunt for evidence of Confluence CVE-2023-22527 exploitation is available on the Velociraptor Artifact Exchange here. Read Rapid7’s blog on sliver tales field
