Google Mandiant and Google Threat Intelligence Group (GTIG) have disclosed that they are tracking a new cluster of activity possibly linked to a financially motivated threat actor known as Cl0p.
The malicious activity involves sending extortion emails to executives at various organizations and claiming to have stolen sensitive data from their Oracle E-Business Suite.
"This activity began on or before September 29, 2025, but Mandiant's experts are still in the early stages of multiple investigations, and have not yet substantiated the claims made by this group," Genevieve Stark, Head of Cybercrime and Information Operations Intelligence Analysis at GTIG, told The Hacker News in a statement.
Stark further said the targeting is opportunistic, as opposed to focusing on specific industries, adding this modus operandi is consistent with prior activity associated with the Cl0p data leak site.
Mandiant CTO Charles Carmakal described the ongoing activity as a "high-volume email campaign" that's launched from hundreds of compromised accounts, with evidence suggesting that at least one of those accounts has been previously associated with activity from FIN11, which is a subset within the TA505 group.
FIN11, per Mandiant, has engaged in ransomware and extortion attacks as far back as 2020. Previously, it was linked to the distribution of various malware families like FlawedAmmyy, FRIENDSPEAK, and MIXLABEL.
"The malicious emails contain contact information, and we've verified that the two specific contact addresses provided are also publicly listed on the Cl0p data leak site (DLS)," Carmakal added. "This move strongly suggests there's some association with Cl0p, and they are leveraging the brand recognition for their current operation."
That said, Google said it does not have any evidence on its own to confirm the alleged ties, despite similarities in tactics observed in past Cl0p attacks. The company is also urging organizations to investigate their environments for evidence of threat actor activity.
It's currently not clear how initial access is obtained. However, according to Bloomberg, it's believed that the attackers compromised user emails and abused the default password reset function to gain valid credentials of internet-facing Oracle E-Business Suite portals, citing information shared by Halycon.
When reached for comment, Oracle told The Hacker News that it's "aware that some Oracle E-Business Suite (EBS) customers have received extortion emails" and that it's ongoing investigation has found the "potential use of previously identified vulnerabilities that are addressed in the July 2025 Critical Patch Update."
Rob Duhart, chief security officer at Oracle Corporation, has also urged customers to apply the latest Critical Patch Update to safeguard against the threat. The company, however, did not say which vulnerabilities are under active exploitation.
In recent years, the highly prolific Cl0p group has been attributed to a number of attack waves exploiting zero-day flaws in Accellion FTA, SolarWinds Serv-U FTP, Fortra GoAnywhere MFT, and Progress MOVEit Transfer platforms, successfully breaching thousands of organizations.
Update
Cybersecurity company Halcyon, in a report published Thursday, said the attackers are abusing the default password reset function to gain valid credentials. Specifically, it relies on local Oracle EBS accounts, bypassing SSO protections owing to the lack of MFA on these accounts, enabling the threat actors to trigger password resets via compromised email accounts and gain valid user access.
"Local accounts bypass enterprise SSO controls and often lack MFA, leaving thousands of organizations exposed," it said in an alert. "Ransom demands have reached up to $50 million, with attackers providing proof of compromise including screenshots and file trees."
(The story was updated after publication to include a response from Oracle and Google, and additional details from Halcyon.)
