Tactic or Technique: Spoofing

Spoofing is when attackers falsify sender information to make a message look like it came from someone you trust by forging a real email address.
Messages like this often impersonate executives, IT support, or vendors and can lead to stolen credentials, wire fraud, or malware infections. When the source looks trustworthy, you're more likely to follow instructions, click a link, or open a file without hesitation.
Spoofing is especially effective when email authentication protocols like SPF, DKIM, and DMARC aren’t properly enforced. Without those protections, it becomes much easier for attackers to get past both technical filters and human judgment.
Rule Name & Severity
Last Updated
Author
Types, Tactics & Capabilities
Headers: Reserved domain in Message-ID
3h ago
Oct 26th, 2026
Sublime Security
Brand impersonation: Federal court system
4h ago
Oct 26th, 2026
Sublime Security
VIP impersonation: Fake thread with name-in-brackets header artifact
6d ago
Oct 21st, 2026
Sublime Security
VIP impersonation: VIP name within a delimited subject with fake previous threads
11d ago
Oct 16th, 2026
Sublime Security
Service abuse: Filemail file-sharing notifications
11d ago
Oct 16th, 2026
Sublime Security
Brand impersonation: MyChart
13d ago
Oct 14th, 2026
Sublime Security
Brand impersonation: Aconex
20d ago
Oct 7th, 2026
Sublime Security
Spoofing: Hidden Outlook headers in self-addressed forwards
21d ago
Oct 6th, 2026
Sublime Security
Service abuse: Google callback scam
21d ago
Oct 6th, 2026
Sublime Security
Brand impersonation: ConstructConnect
21d ago
Oct 6th, 2026
Sublime Security
Link: Observed URL path (lht) with recipient email address
21d ago
Oct 6th, 2026
Sublime Security
Brand impersonation: Google Authenticator
25d ago
Oct 2nd, 2026
Sublime Security
Attachment: ICS invite meeting lure
29d ago
Sep 28th, 2026
Sublime Security
Body: Embedded email headers indicative of thread hijacking/abuse
1mo ago
Sep 23rd, 2026
Sublime Security
Extortion / sextortion (untrusted sender)
1mo ago
Sep 23rd, 2026
Sublime Security
VIP local_part impersonation from unsolicited sender
1mo ago
Sep 23rd, 2026
Sublime Security
Brand impersonation: Navan
1mo ago
Sep 23rd, 2026
Sublime Security
Brand impersonation: State Farm
1mo ago
Sep 23rd, 2026
Sublime Security
Brand impersonation: Survey request with credential theft indicators
1mo ago
Sep 22nd, 2026
Sublime Security
Brand impersonation: Sedgwick Claims
1mo ago
Sep 18th, 2026
Sublime Security