Cybercriminals are leveraging vulnerabilities in JetBrains TeamCity software to deploy BianLian ransomware for extortion attacks. The BianLian threat actors exploit these flaws for ransomware attacks, shifting focus to extortion-only tactics. The group also deploys a PowerShell backdoor through TeamCity. Researchers highlight the exploitation of known bugs in TeamCity by the BianLian ransomware gang to gain access to victims' systems. JetBrains expresses frustration towards Rapid7 for the ransomware attacks on its customers.