bleepingcomputer.com - Law enforcement has seized the dark web leak sites of the BlackSuit ransomware operation, which has targeted and breached the networks of hundreds of organizations worldwide over the past several years.
The U.S. Department of Justice confirmed the takedown in an email earlier today, saying the authorities involved in the action executed a court-authorized seizure of the BlackSuit domains.
Earlier today, the websites on the BlackSuit .onion domains were replaced with seizure banners announcing that the ransomware gang's sites were taken down by the U.S. Homeland Security Investigations federal law enforcement agency as part of a joint international action codenamed Operation Checkmate.
"This site has been seized by U.S. Homeland Security Investigations as part of a coordinated international law enforcement investigation," the banner reads.
Other law enforcement authorities that joined this joint operation include the U.S. Secret Service, the Dutch National Police, the German State Criminal Police Office, the U.K. National Crime Agency, the Frankfurt General Prosecutor's Office, the Justice Department, the Ukrainian Cyber Police, Europol, and others.
Romanian cybersecurity company Bitdefender was also involved in the action, but a spokesperson has yet to reply after BleepingComputer reached out for more details earlier today.
Chaos ransomware rebrand
On Thursday, the Cisco Talos threat intelligence research group reported that it had found evidence suggesting the BlackSuit ransomware gang is likely to rebrand itself once again as Chaos ransomware.
"Talos assesses with moderate confidence that the new Chaos ransomware group is either a rebranding of the BlackSuit (Royal) ransomware or operated by some of its former members," the researchers said.
"This assessment is based on the similarities in TTPs, including encryption commands, the theme and structure of the ransom note, and the use of LOLbins and RMM tools in their attacks."
BlackSuit started as Quantum ransomware in January 2022 and is believed to be a direct successor to the notorious Conti cybercrime syndicate. While they initially used encryptors from other gangs (such as ALPHV/BlackCat), they deployed their own Zeon encryptor soon after and rebranded as Royal ransomware in September 2022.
In June 2023, after targeting the City of Dallas, Texas, the Royal ransomware gang began working under the BlackSuit name, following the testing of a new encryptor called BlackSuit amid rumors of a rebranding.
CISA and the FBI first revealed in a November 2023 joint advisory that Royal and BlackSuit share similar tactics, while their encryptors exhibit obvious coding overlaps. The same advisory linked the Royal ransomware gang to attacks targeting over 350 organizations worldwide since September 2022, resulting in ransom demands exceeding $275 million.
The two agencies confirmed in August 2024 that the Royal ransomware had rebranded as BlackSuit and had demanded over $500 million from victims since surfacing more than two years prior.
microsoft.com - July 23, 2025 update – Expanded analysis and threat intelligence from our continued monitoring of exploitation activity by Storm-2603 leading to the deployment of Warlock ransomware. Based on new information, we have updated the Attribution, Indicators of compromise, extended and clarified Mitigation and protection guidance (including raising Step 6: Restart IIS for emphasis), Detections, and Hunting sections.
On July 19, 2025, Microsoft Security Response Center (MSRC) published a blog addressing active attacks against on-premises SharePoint servers that exploit CVE-2025-49706, a spoofing vulnerability, and CVE-2025-49704, a remote code execution vulnerability. These vulnerabilities affect on-premises SharePoint servers only and do not affect SharePoint Online in Microsoft 365. Microsoft has released new comprehensive security updates for all supported versions of SharePoint Server (Subscription Edition, 2019, and 2016) that protect customers against these new vulnerabilities. Customers should apply these updates immediately to ensure they are protected.
These comprehensive security updates address newly disclosed security vulnerabilities in CVE-2025-53770 that are related to the previously disclosed vulnerability CVE-2025-49704. The updates also address the security bypass vulnerability CVE-2025-53771 for the previously disclosed CVE-2025-49706.
As of this writing, Microsoft has observed two named Chinese nation-state actors, Linen Typhoon and Violet Typhoon exploiting these vulnerabilities targeting internet-facing SharePoint servers. In addition, we have observed another China-based threat actor, tracked as Storm-2603, exploiting these vulnerabilities to deploy ransomware. Investigations into other actors also using these exploits are still ongoing. With the rapid adoption of these exploits, Microsoft assesses with high confidence that threat actors will continue to integrate them into their attacks against unpatched on-premises SharePoint systems. This blog shares details of observed exploitation of CVE-2025-49706 and CVE-2025-49704 and the follow-on tactics, techniques, and procedures (TTPs) by threat actors. We will update this blog with more information as our investigation continues.
Microsoft recommends customers to use supported versions of on-premises SharePoint servers with the latest security updates. To stop unauthenticated attacks from exploiting this vulnerability, customers should also integrate and enable Antimalware Scan Interface (AMSI) and Microsoft Defender Antivirus (or equivalent solutions) for all on-premises SharePoint deployments and configure AMSI to enable Full Mode as detailed in Mitigations section below. Customers should also rotate SharePoint server ASP.NET machine keys, restart Internet Information Services (IIS), and deploy Microsoft Defender for Endpoint or equivalent solutions.
