alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Coldstealer Sending System Information (POST)"; flow:established,to_server; urilen:1; http.method; content:"POST"; http.header_names; content:"|0d 0a|Host|0d 0a|Content-Length|0d 0a|Expect|0d 0a|Connection|0d 0a 0d 0a|"; bsize:46; http.request_body; content:"PK"; startswith; content:"Information.txt"; distance:0; fast_pattern; reference:md5,06b31367d65a411b1f2a7b3091fb31d4; reference:url,securelist.com/nullmixer-oodles-of-trojans-in-a-single-dropper/107498/; classtype:trojan-activity; sid:2039040; rev:1; metadata:attack_target Client_Endpoint, created_at 2022_09_29, malware_family Win32_Coldstealer, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_09_29;)