alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET DELETED Win32/Rallovs.A CnC Beacon"; flow:established,to_server; dsize:>1000; content:"|00 00 00 00|2|00|0|00|"; fast_pattern; pcre:"/^[1-9]\x00\d/R"; content:"|00|-|00|"; within:3; pcre:"/^\d\x00\d/R"; content:"|00|-|00|"; within:3; pcre:"/^\d\x00\d/R"; content:"|00 20 00|"; within:3; pcre:"/^\d\x00\d/R"; content:"|00 3a 00|"; within:3; pcre:"/^\d\x00\d/R"; content:"|00 3a 00|"; pcre:"/^\d\x00\d/R"; content:"|00 00|2|00|0|00|"; distance:0; content:"|00|-|00|"; distance:3; within:3; reference:md5,67a039a3139c6ef1bf42424acf658d01; reference:url,blog.cylance.com/spear-a-threat-actor-resurfaces; classtype:command-and-control; sid:2021117; rev:3; metadata:attack_target Client_Endpoint, created_at 2015_05_19, deployment Perimeter, signature_severity Major, tag c2, updated_at 2019_07_26, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)