diff --git a/detection-rules/link_romance_suspicious.yml b/detection-rules/link_romance_suspicious.yml new file mode 100644 index 00000000000..d485b327793 --- /dev/null +++ b/detection-rules/link_romance_suspicious.yml @@ -0,0 +1,36 @@ +name: "Link: Romance/Sexual Language With Suspicious Link" +description: "Detects messages containing romantic or adult-themed language, combined with links to newly registered domains or suspicious reply-to addresses." +type: "rule" +severity: "low" +source: | + type.inbound + and any(beta.ml_topic(body.current_thread.text).topics, + .name in ("Romance", "Sexually Explicit Messages") + and .confidence == "high" + ) + and 1 of ( + any(body.links, network.whois(.href_url.domain).days_old < 30), + any(body.links, .href_url.domain.root_domain in $url_shorteners), + any(headers.reply_to, network.whois(.email.domain).days_old < 30), + any(headers.reply_to, + .email.domain.root_domain != sender.email.domain.root_domain + ) + ) + and 0 < length(distinct(body.links, + .href_url.domain.root_domain not in ("aka.ms") + ) + ) < 3 + and all(body.links, + .href_url.domain.root_domain != sender.email.domain.root_domain + ) + +attack_types: + - "Spam" +tactics_and_techniques: + - "Social engineering" +detection_methods: + - "Content analysis" + - "Header analysis" + - "URL analysis" + - "Whois" +id: "d5694cae-bee8-588e-8123-2c3e3459118b"