Cobalt Strike 4.11.1 is now available. This is an out of band update to fix an issue regarding module stomping that was discovered in the 4.11 release that we felt should be fixed prior to the next release. Besides that issue, this out of band release also allowed us to include two other smaller bugfixes/quality […]
CTA Type: Blog
Cobalt Strike 4.11: Shhhhhh, Beacon is Sleeping….
Cobalt Strike 4.11 is now available. This release introduces a novel Sleepmask, a novel process injection technique, new out-of-the-box obfuscation options for Beacon, asynchronous BOFs, and a DNS over HTTPS (DoH) Beacon. Additionally, we have overhauled Beacon’s reflective loader and there are numerous QoL updates. Out-of-the-Box Evasion Overhaul The focus of this release (and the […]
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Update: Stopping Cybercriminals from Abusing Cobalt Strike
Since 2023, Microsoft’s Digital Crimes Unit (DCU), Fortra, and the Health Information Sharing and Analysis Center (Health-ISAC) have been working together to combat the use of unauthorized, legacy copies of Cobalt Strike and compromised Microsoft software, which have been weaponized by cybercriminals to deploy ransomware and other malware, causing significant harm to critical sectors like […]
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Out of Band Update: Cobalt Strike 4.10.1
Cobalt Strike 4.10.1 is now available. This is an out of band update to fix issues that were discovered in Cobalt Strike 4.10 that we felt should be fixed before the next release. This update does not affect the 4.11 release which is well underway and due to ship in early 2025. Mutiple Team Server […]
Cobalt Strike Staffing Changes and the Road Ahead
TLDR: Cobalt Strike Staffing Changes Recently there have been some internal changes within the Cobalt Strike team. Greg Darwin has switched to a new position within Fortra. Greg has been the face of Cobalt Strike within the community for a number of years and we thank Greg for all his work and effort he put […]
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Revisiting the UDRL Part 3: Beacon User Data
The UDRL and the Sleepmask are key components of Cobalt Strike’s evasion strategy, yet historically they have not worked well together. For example, prior to CS 4.10, Beacon statically calculated its location in memory using a combination of its base address and its section table. This calculation was then modified depending on the contents of […]
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Cobalt Strike 4.10: Through the BeaconGate
Cobalt Strike 4.10 is now available. This release introduces BeaconGate, the Postex Kit, and Sleepmask-VS. In addition, we have overhauled the Sleepmask API, refreshed the Jobs UI, added new BOF APIs, added support for hot swapping C2 hosts, and more. This has been a longer release cycle than in previous releases to allow us to […]
Europol Coordinates Global Action Against Criminal Abuse of Cobalt Strike
Press Release: View Original Europol Announcement 03 Jul 2024 – Law enforcement has teamed up with the private sector to fight against the abuse of a legitimate security tool by criminals who were using it to infiltrate victims’ IT systems. Older, unlicensed versions of the Cobalt Strike red teaming tool were targeted during a week […]
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Cobalt Strike Infrastructure Downtime – March 2024
The Cobalt Strike download infrastructure will be down for a short while on Wednesday 13th March for routine maintenance. Work will begin around 15:00 GMT (10:00 EST). We expect the maintenance to be completed in under 30 minutes. Downloads and updates will be unavailable while this work is carried out. Apologies for any inconvenience that […]
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Introducing the Mutator Kit: Creating Object File Monstrosities with Sleep Mask and LLVM
This is a joint blog written by William Burgess (@joehowwolf) and Henri Nurmi (@HenriNurmi). In our ‘Cobalt Strike and YARA: Can I Have Your Signature?’ blog post, we highlighted that the sleep mask is a common target for in-memory YARA signatures. In that post we recommended using the evasive sleep mask option to scramble the […]