alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE DonotGroup Maldoc Activity (GET)"; flow:established,to_server; http.method; content:"GET"; http.uri; pcre:"/^\/[A-Za-z0-9]{16}\/[A-Za-z0-9]{48}\.ico$/"; content:"/"; startswith; content:"/"; distance:16; within:1; content:".ico"; distance:48; within:4; endswith; fast_pattern; http.header_names; content:"|0d 0a|Accept|0d 0a|Accept-Encoding|0d 0a|User-Agent|0d 0a|Host|0d 0a|Connection|0d 0a 0d 0a|"; bsize:59; reference:md5,64266fc0f0b37a26e14133ad19b98b7c; reference:url,twitter.com/Timele9527/status/1597955256423309312; classtype:trojan-activity; sid:2041452; rev:1; metadata:attack_target Client_Endpoint, created_at 2022_11_30, deployment Perimeter, malware_family DonotGroup, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_02_14; target:src_ip;)