File sharing link from suspicious sender domain
A file sharing link in the body sent from a suspicious sender domain.
Sublime rule (View on GitHub)
1name: "File sharing link from suspicious sender domain"
2description: |
3 A file sharing link in the body sent from a suspicious sender domain.
4type: "rule"
5severity: "medium"
6source: |
7 type.inbound
8 and any(body.links,
9 (
10 .href_url.domain.domain in $free_file_hosts
11 or .href_url.domain.root_domain in $free_file_hosts
12 )
13 // remove free_file_hosts used to host images as links
14 and not any($file_types_images,
15 strings.iends_with(..href_url.url, strings.concat('.', .))
16 )
17 )
18 and sender.email.domain.tld in $suspicious_tlds
19 and (
20 not profile.by_sender().solicited
21 or (
22 profile.by_sender().any_messages_malicious_or_spam
23 and not profile.by_sender().any_false_positives
24 )
25 )
26
27tags:
28 - "Attack surface reduction"
29attack_types:
30 - "Credential Phishing"
31 - "Malware/Ransomware"
32tactics_and_techniques:
33 - "Free file host"
34detection_methods:
35 - "Sender analysis"
36 - "URL analysis"
37id: "95f20354-3091-537e-9fe0-80ea8b64913b"