Open redirect: Linkedin

 1name: "Open redirect: Linkedin"
 2description: "Detects emails containing links using Linkedin '/slink?code=xxxxx' open redirect where the email has not come from Linkedin.com"
 3references:
 4  - "https://krebsonsecurity.com/2022/02/how-phishers-are-slinking-their-links-into-linkedin/"
 5type: "rule"
 6authors:
 7  - twitter: "xNymia"
 8severity: "medium"
 9source: |
10  type.inbound
11  and (
12    (
13      sender.email.domain.root_domain != "linkedin.com"
14      and any(body.links,
15              .href_url.domain.root_domain == 'linkedin.com' and .href_url.path == '/slink'
16      )
17      and any(body.links, strings.ilike(.href_url.query_params, 'code=*'))
18    )
19    or any(attachments,
20           .file_type == "pdf"
21           and any(file.explode(.),
22                   any(.scan.url.urls, .domain.root_domain == 'linkedin.com' and .path == '/slink')
23                   and any(.scan.url.urls, strings.ilike(.query_params, 'code=*'))
24           )
25    )
26  )  
27tags:
28  - "Attack surface reduction"
29attack_types:
30  - "Credential Phishing"
31  - "Malware/Ransomware"
32tactics_and_techniques:
33  - "Open redirect"
34detection_methods:
35  - "Sender analysis"
36  - "URL analysis"
37id: "5ad2ffae-fca7-58ff-90bd-8efbd98c0a72"