alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MOBILE_MALWARE Android.Trojan.SLocker.DZ Checkin 2"; flow:to_server,established; http.method; content:"GET"; nocase; http.uri; content:"/gac/"; fast_pattern; pcre:"/^\/gac\/[a-f0-9]{15}$/"; http.header; content:"|0d 0a|Connection|3a 20|Keep-Alive|0d 0a|Accept-Encoding|3a 20|gzip|0d 0a|"; http.user_agent; content:"|20|Android|20|"; http.header_names; content:!"Referer|0d 0a|"; reference:url,blog.fortinet.com/post/locker-an-android-ransomware-full-of-surprises; classtype:trojan-activity; sid:2021617; rev:5; metadata:affected_product Android, attack_target Mobile_Client, created_at 2015_08_13, deployment Perimeter, signature_severity Major, tag Android, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_10_01, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)