alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Gamaredon APT Related Activity (GET)"; flow:established,to_server; urilen:>25; http.uri; content:".sis"; endswith; fast_pattern; http.user_agent; content:"|3b 20|ms-office|3b 20|"; http.header_names; to_lowercase; content:!"|0d 0a|referer|0d 0a|"; reference:md5,eae6501eca7f6f7a1df447ab68d97932; reference:md5,80a7b2699e245f8cd1ae58f22dc336a2; reference:url,twitter.com/StopMalvertisin/status/1625032155255689216; classtype:trojan-activity; sid:2044197; rev:3; metadata:created_at 2023_02_13, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_26, reviewed_at 2023_11_06; target:src_ip;)