Rule History

SID: 2041131 • Source: et/open

Versions (5)

Version DetailsCurrent

Rev: 1 • Nov 30, 2022, 12:00 PM

Message:

ET USER_AGENTS Microsoft Office Existence Discovery User-Agent

Rule:

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET USER_AGENTS Microsoft Office Existence Discovery User-Agent"; flow:established,to_server; http.user_agent; content:"Microsoft Office Existence Discovery"; bsize:36; threshold:type both, track by_src, count 1, seconds 600; classtype:misc-activity; sid:2041131; rev:1; metadata:attack_target Client_Endpoint, created_at 2022_11_30, deployment Perimeter, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_11_30, reviewed_at 2025_10_24;)

Created:

Nov 30, 2022, 12:00 PM

Updated:

Nov 30, 2022, 12:00 PM

DB Created:

Sep 21, 2024, 3:00 AM

DB Updated:

Oct 24, 2025, 9:34 PM

Filename:

rules/emerging-user_agents.rules