alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE ACR/Amatera Stealer CnC Checkin Attempt M1"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/ujs/"; fast_pattern; startswith; pcre:"/^[a-f0-9]{8}-(?:[a-f0-9]{4}-){3}[a-f0-9]{12}$/R"; reference:url,malpedia.caad.fkie.fraunhofer.de/details/win.acr_stealer; reference:url,threatfox.abuse.ch/browse/malware/win.acr_stealer/; classtype:trojan-activity; sid:2052674; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Windows_11, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2024_05_16, deployment Perimeter, deployment SSLDecrypt, malware_family Amatera, performance_impact Low, confidence High, signature_severity Major, updated_at 2024_05_16; target:src_ip;)