Malicious New Member Added to a "OCS/Lync/Skype for Business" Administration Group - Medium Risk (via security)
- Product
- windows
- Service
- security
- Author
- HuntRule
- Published
- 2026-07-24
- Updated
- 2026-08-28
ATT&CK techniques
Persistence → Priv EscRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule detects scenarios where a new member is added to a sensitive administration group related to OCS/Lync/Skype for Business in order to scan topology, infiltrate servers and move laterally.
Reporting behind it
- attack.mitre.orghttps://attack.mitre.org/techniques/T1098/
- docs.microsoft.comhttps://docs.microsoft.com/en-us/previous-versions/office/lync-server-2013/lync-server-2013-planning-for-role-based-access-control
- docs.microsoft.comhttps://docs.microsoft.com/en-us/skypeforbusiness/schema-reference/active-directory-schema-extensions-classes-and-attributes/changes-made-by-forest-preparation
- blog.insideo365.comhttps://blog.insideo365.com/2012/11/a-lync-administrator-access-refresher/
- ultimatewindowssecurity.comhttps://www.ultimatewindowssecurity.com/securitylog/encyclopedia/event.aspx?eventID=4728
- ultimatewindowssecurity.comhttps://www.ultimatewindowssecurity.com/securitylog/encyclopedia/event.aspx?eventID=4732
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
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