alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET WEB_CLIENT Possible Embedded NTLM Hash Theft Code"; flow:established,to_client; file.data; content:"src=file|3a 2f 2f 2f 5c 5c|"; nocase; fast_pattern; content:"|5f|C$|5f|"; nocase; within:50; content:"visibility|3a|"; nocase; within:50; content:"hidden"; within:8; content:"src="; pcre:"/^\s*[\x22\x27]\s*file\x3a\x2f\x2f\x2f\x5c\x5c[^\x20]+\x5cC\$\x5c\s*[\x22\x27]/Rsi"; reference:url,unit42.paloaltonetworks.com/xhunt-campaign-new-watering-hole-identified-for-credential-harvesting; classtype:attempted-user; sid:2029329; rev:3; metadata:attack_target Client_Endpoint, created_at 2020_01_29, deployment Perimeter, confidence Medium, signature_severity Minor, updated_at 2023_10_11, reviewed_at 2024_04_30;)