Hey everyone, nothing like a Friday night full of security fun.
We've confirmed unauthorized sign-ins within 173 partner/customer tenants using the originally compromised vendor credential for ConnectWise Cloud Backup (formerly SkyKick).
Separately, we've observed notable new activity: abuse of an additional ConnectWise M365 application (ConnectWise Cloud Management - MS Teams, Application ID 24205314-2b89-4e07-a2a4-579e898a5640) that gave itself Global Administrator and added credentials to multiple applications (including our single-tenant Huntress application unique to this partner's tenant). Microsoft's sign-in logs recorded this second application connection coming from a private IPv6 address (ULA) fde4:8dba:2600:37ce:6d26:200:a76:*, a range Microsoft logs for traffic inside its own cloud network. We strongly suggest you audit your M365 environments for this immediately.
Legitimate ConnectWise traffic and unrelated customer traffic also appears to originate from the same ULA, so please consider the address alone does not identify who operated the system. We are working to determine that.
Microsoft is aware of the situation. Expect more to come on this.
We'll be monitoring this thread closely and keeping our blog up to date with all new observations:
Update 1 - 17 October, 2026 @ 0933 ET
After spending the night combing through Azure logs, we have high-confidence that the threat actor has also abused the following M365 applications:
- ConnectWise Cloud Management - Exchange Online (b78f6a77-d4e5-46fb-87e5-d1648bd02519)
- ConnectWise Cloud Management - MS Teams (24205314-2b89-4e07-a2a4-579e898a5640)
- ConnectWise Cloud Management - SharePoint Online (b2b55f5b-7758-4719-8d8f-88ae172e6bdb)
ConnectWise has disabled each of these apps to mitigate potential abuse. At the moment, it does not look like these apps have been disabled by ConnectWise. Massive kudos to u/Mother-Speed-837 for observing and reporting the same this morning đ
When it comes to early exploitation and post-exploitation behaviors, weâve observed use of IPs other than 144.172.64[.]128 and what might be an affinity towards alphabetical targeting (our most interesting victims start with âAâ). Although all tenants should be scrutinized, this pattern is worth sharing for prioritization.
If youâve been impacted with noteworthy tradecraft relating to this Skykick incident, our research team would love to learn more so we take actions to protect the community. Hit us up at [support@huntress.com](mailto:support@huntress.com).
Update 2 - 17 October, 2026 @ 1716 ET
Further analysis has uncovered targeted failed attempts to access tenants in the foreign policy, national security, trade, and critical mineral sectors. This particular âsweepâ of failed connections hit tenants manually and more slowly than our previous observed automated connections and happened between 13:54:39 to 14:20:24 UTC on October 15. It fixated on Exchange Online, SharePoint Online, Teams, Azure Resource Manager, Entra, and the Office 365 Management APIs.
We are actively coordinating with law enforcement and impacted organizations behind the scenes and will continue to share more as this situation progresses.