HighSigmaHQ Florian Roth (Nextron Systems)

Suspicious MSExchangeMailboxReplication ASPX Write

Detects suspicious activity in which the MSExchangeMailboxReplication process writes .asp and .apsx files to disk, which could be a sign of ProxyShell exploitation

Detection logic

Detection requirements

Platform: Containers ESXi IaaS Linux macOS Network Devices Windows
The rule states no platform. This is derived from the 2 ATT&CK techniques it maps to.
Log source product: windows
Log source category: file_event

Known benign triggers

Unknown

References

Links the source published beside this detection. Reference is the link the source wrote, unmodified. Class is decided by this catalogue from the host and path, not stated by the source. Cited by counts published detections citing the same resource, including this one, and the sources beneath it count the repositories this catalogue ingests, which is not the same as independent research.
Reference	Class	Cited by
redcanary.com/blog/blackbyte-ransomware/	Security research	6from 2 sources

Detection rules

Suspicious MSExchangeMailboxReplication ASPX Write

Detection logic

Detection requirements

Known benign triggers

MITRE ATT&CK mappings

References

From the source

Licence

Authorship

Detection rules