Full Report
A group of Russian state-supported cyber actors has been targeting and compromisingvarious Western government and commercial organizations using the ZimbraCollaboration Suite (ZCS) software since at least July 2025. The Russian state-supported advanced persistent threat (APT) group’s activity is tracked in thecybersecurity community under several names, primarily as “LAUNDRY BEAR,” a name initially coined by the…
Analysis Summary
# Threat Actor: LAUNDRY BEAR
## Attribution & Identity
* **Actor Name:** LAUNDRY BEAR
* **Attribution:** Russian state-supported advanced persistent threat (APT) group.
* **Identity Source:** The name "LAUNDRY BEAR" was initially coined by the Netherlands General Intelligence and Security Service (AIVD) and the Defence Intelligence and Security Service (MIVD).
## Activity Summary
Since at least July 2025, LAUNDRY BEAR has been engaged in a sustained campaign targeting Western government and commercial organizations. The group specifically leverages vulnerabilities in the Zimbra Collaboration Suite (ZCS) to compromise targets. Most recently, they transitioned from unsophisticated volume attacks to the use of a novel zero-day exploit (CVE-2025-66376) to gain unauthorized access.
## Tactics, Techniques & Procedures
* **Initial Access:**
* Password Spraying
* Phishing
* Pass-the-Cookie
* Exploitation of Public-Facing Applications
* **Exploitation:** Use of zero-day vulnerabilities (CVE-2025-66376).
* **Objective:** Covert acquisition of email data and sensitive information gathering.
* **MITRE ATT&CK IDs:**
* T1589 (Gather Victim Identity Information)
* T1110.003 (Brute Force: Password Spraying)
* T1566 (Phishing)
* T1550.004 (Use Alternate Authentication Material: Pass the Cookie)
* T1190 (Exploit Public-Facing Application)
## Targeting
* **Sectors:** Western government agencies and commercial organizations.
* **Geography:** Primarily Western nations (Europe and North America).
* **Victims:** Users of the Zimbra Collaboration Suite (ZCS).
## Tools & Infrastructure
* **Vulnerabilities Exploited:** CVE-2025-66376 (Zimbra Collaboration Suite vulnerability, patched in November 2025).
* **Malware/Software:** Zimbra Collaboration Suite (ZCS) is the primary target for exploitation and data exfiltration.
## Implications
LAUNDRY BEAR represents a significant threat to diplomatic and commercial communications. Their ability to pivot from high-volume, unsophisticated "noise" attacks to the discovery and utilization of zero-day exploits indicates a high level of operational maturity and resource backing. The focus on email data suggests a strategic mission centered on espionage and long-term intelligence gathering for the Russian Federation.
## Mitigations
* **Patch Management:** Immediately update Zimbra Collaboration Suite to address CVE-2025-66376 (patched as of November 2025).
* **Authentication Security:** Implement Robust Multi-Factor Authentication (MFA) to mitigate password spraying and pass-the-cookie attacks.
* **Session Security:** Regularly rotate session tokens and implement strict session timeouts to reduce the effectiveness of cookie theft.
* **Monitoring:** Monitor for unusual login patterns or high-volume data exfiltration from mail servers.