alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE NCSC XAgent itwm beacon v2"; flow:established,to_server; content:"&itwm"; fast_pattern; pcre:"/&itwm=[A-Za-z0-9\-\_]{29,35}/"; reference:url,www.ncsc.gov.uk/content/files/protected_files/article_files/IOC-APT28-malware-advisory.pdf; classtype:targeted-activity; sid:2026439; rev:1; metadata:attack_target Client_Endpoint, created_at 2018_10_04, deployment Perimeter, confidence Medium, 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;)