alert tcp $EXTERNAL_NET 1024:65535 -> $HOME_NET any (msg:"ET MALWARE Bandook v1.35 Keepalive Send"; flow:established,to_client; flowbits:isset,BE.Bandook1.35; dsize:6; content:"|cf ab a8 a7 ae cf|"; offset:0; reference:url,www.nuclearwintercrew.com; reference:url,research.sunbelt-software.com/threatdisplay.aspx?name=Bandook&threatid=40408; classtype:trojan-activity; sid:2003556; rev:8; metadata:created_at 2010_07_30, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_03_15;)