From volexity.com
Over the Memorial Day weekend in the United States, Volexity conducted an incident response investigation involving two Internet-facing web servers belonging to one of its customers that were running Atlassian Confluence Server software. The investigation began after suspicious activity was detected on the hosts, which included JSP webshells being written to disk. Volexity immediately used Volexity Surge Collect Pro to collect system memory and key files from the Confluence Server systems for analysis. After a thorough review of the collected data, Volexity was able to determine the server compromise stemmed from an attacker launching an exploit to achieve remote code execution. Volexity was subsequently able to recreate that exploit and identify a zero-day vulnerability impacting fully up-to-date versions of Confluence Server.