Detection Method: Whois

Whois analysis retrieves and examines domain registration information from global Whois databases to spot suspicious or recently created domains that could indicate phishing attempts. This method helps you understand key domain details like the age, ownership, and registration patterns, which can be red flags for malicious activity.
Whois analysis can detect:
  • Newly registered domains that might have been set up just for phishing campaigns
  • Domains with suspicious registration patterns or incomplete Whois records
  • Mismatched registration details that don’t align with the claimed organization
  • Domains registered via privacy services to conceal true ownership
  • Domains with upcoming expiration dates, which could indicate temporary use
For example, established organizations often use domains that have been registered for long periods. So, if you get an email from a financial institution using a domain that was registered only a few days ago, that’s a huge red flag.
Rule Name & Severity
Last Updated
Author
Types, Tactics & Capabilities
Suspicious newly registered reply-to domain with engaging financial or urgent language
6d ago
May 6th, 2026
Sublime Security
Link: Romance/Sexual Language With Suspicious Link
7d ago
May 5th, 2026
Sublime Security
Service abuse: Zoom with newly registered reply-to domain
8d ago
May 4th, 2026
Sublime Security
Brand impersonation: SharePoint PDF attachment with credential theft language
8d ago
May 4th, 2026
Sublime Security
Impersonation: Suspected supplier impersonation with suspicious content
8d ago
May 4th, 2026
Sublime Security
Attachment: Calendar invite from recently registered domain
14d ago
Apr 28th, 2026
Sublime Security
Attachment: ICS file with links to newly registered domains
22d ago
Apr 20th, 2026
Sublime Security
BEC/Fraud: Urgent language and suspicious sending/infrastructure patterns
25d ago
Apr 17th, 2026
Sublime Security
Link: Tax document lure Portuguese/Spanish with suspicious domains
28d ago
Apr 14th, 2026
Sublime Security
Service abuse: GitHub notification with excessive mentions and suspicious links
1mo ago
Apr 7th, 2026
Sublime Security
VIP impersonation: Fake thread with display name match, email mismatch
1mo ago
Apr 3rd, 2026
Sublime Security
Attachment: Legal themed message or PDF with suspicious indicators
1mo ago
Apr 3rd, 2026
Sublime Security
Service abuse: Google Firebase sender address with suspicious content
1mo ago
Apr 2nd, 2026
Sublime Security
Link: Financial account issue with suspicious indicators
1mo ago
Mar 24th, 2026
Sublime Security
Link: Commonly Abused Web Service redirecting to ZIP file
2mo ago
Mar 10th, 2026
Sublime Security
Link: Multistage landing - ClickUp abuse
2mo ago
Feb 27th, 2026
Sublime Security
Attachment: PDF with multistage landing - ClickUp abuse
2mo ago
Feb 27th, 2026
Sublime Security
New link domain (<=10d) from untrusted sender
3mo ago
Feb 6th, 2026
Sublime Security
Vendor impersonation: Thread hijacking with typosquat domain
3mo ago
Jan 12th, 2026
Sublime Security
Suspected lookalike domain with suspicious language
3mo ago
Jan 12th, 2026
Sublime Security