LowSigmaHQ Florian Roth (Nextron Systems)

PowerShell Download Via Net.WebClient - PowerShell Classic

Detects PowerShell download activity, via the .DownloadFile() or .DownloadString() methods of the Net.WebClient class. This technique is often abused by attackers to download additional payloads.

Detection logic

Detection requirements

Platform: ESXi 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: ps_classic_start

Known benign triggers

This activity may be used by legitimate software, such as patch management tools or software updaters. Investigate any such activity and apply the necessary filter.

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
www.trendmicro.com/en_us/research/22/j/lv-ransomware-exploits-proxyshell-in-attack.html	Threat report	3

Detection rules

PowerShell Download Via Net.WebClient - PowerShell Classic

Detection logic

Detection requirements

Known benign triggers

MITRE ATT&CK mappings

References

From the source

Licence

Authorship

Detection rules