ET MALWARE StealC v2 Fake 404 Page Observed


Query · suricata

flow:established,to_client;
http.response_body; bsize:<435;
content:"|3c 21|DOCTYPE|20|html|3e|"; startswith;
content:"|3c 21|DOCTYPE|20|html|3e 0a 3c|html|3e 0a 3c|head|3e 0a 20 20 20 20 3c|meta|20|charset|3d 22|utf|2d|8|22 3e 0a 20 20 20 20 3c|title|3e|404|20|Not|20|Found|3c 2f|title|3e 0a 20 20 20 20 3c|style|3e 0a 20 20 20 20 20 20 20 20|body|20 7b 0a 20 20 20 20 20 20 20 20 20 20 20 20|width|3a 20|35em|3b 0a 20 20 20 20 20 20 20 20 20 20 20 20|margin|3a 20|0|20|auto|3b 0a 20 20 20 20 20 20 20 20 20 20 20 20|font|2d|family|3a 20|Tahoma|2c 20|Verdana|2c 20|Arial|2c 20|sans|2d|serif|3b 0a 20 20 20 20 20 20 20 20 7d 0a 20 20 20 20 3c 2f|style|3e 0a 3c 2f|head|3e 0a 3c|body|3e 0a 20 20 20 20 3c|h1|3e|Not|20|Found|3c 2f|h1|3e 0a 20 20 20 20 3c|p|3e|The|20|requested|20|URL|20|was|20|not|20|found|20|on|20|this|20|server|2e 3c 2f|p|3e 0a 20 20 20 20 3c|hr|3e 0a 20 20 20 20 3c|address|3e|nginx|2f|1|2e|18|2e|0|20 28|Ubuntu|29 3c 2f|address|3e 0a 3c 2f|body|3e 0a 3c 2f|html|3e|"; fast_pattern;
target:dest_ip;
Raw source ET MALWARE StealC v2 Fake 404 Page Observed · Suricata
Esc
Published by Emerging Threats Open ↗, licensed under BSD 3-Clause ↗. Line breaks added for readability; the rule is otherwise unchanged.
alert http $EXTERNAL_NET any -> $HOME_NET any (
    msg:"ET MALWARE StealC v2 Fake 404 Page Observed";
    flow:established,to_client;
    http.response_body; bsize:<435;
    content:"|3c 21|DOCTYPE|20|html|3e|"; startswith;
    content:"|3c 21|DOCTYPE|20|html|3e 0a 3c|html|3e 0a 3c|head|3e 0a 20 20 20 20 3c|meta|20|charset|3d 22|utf|2d|8|22 3e 0a 20 20 20 20 3c|title|3e|404|20|Not|20|Found|3c 2f|title|3e 0a 20 20 20 20 3c|style|3e 0a 20 20 20 20 20 20 20 20|body|20 7b 0a 20 20 20 20 20 20 20 20 20 20 20 20|width|3a 20|35em|3b 0a 20 20 20 20 20 20 20 20 20 20 20 20|margin|3a 20|0|20|auto|3b 0a 20 20 20 20 20 20 20 20 20 20 20 20|font|2d|family|3a 20|Tahoma|2c 20|Verdana|2c 20|Arial|2c 20|sans|2d|serif|3b 0a 20 20 20 20 20 20 20 20 7d 0a 20 20 20 20 3c 2f|style|3e 0a 3c 2f|head|3e 0a 3c|body|3e 0a 20 20 20 20 3c|h1|3e|Not|20|Found|3c 2f|h1|3e 0a 20 20 20 20 3c|p|3e|The|20|requested|20|URL|20|was|20|not|20|found|20|on|20|this|20|server|2e 3c 2f|p|3e 0a 20 20 20 20 3c|hr|3e 0a 20 20 20 20 3c|address|3e|nginx|2f|1|2e|18|2e|0|20 28|Ubuntu|29 3c 2f|address|3e 0a 3c 2f|body|3e 0a 3c 2f|html|3e|"; fast_pattern;
    reference:url,x.com/g0njxa/status/1910366345809530929;
    classtype:trojan-activity;
    sid:2061789; rev:1;
    metadata:attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2025_04_22, deployment Perimeter, deployment SSLDecrypt, malware_family Stealc, confidence Medium, signature_severity Major, updated_at 2025_04_22;
    target:dest_ip;
)

Detection rules belong to the projects that publish them and remain under their own licenses. This site indexes and links to them; it claims no rights in them.