Tactic or Technique: Free email provider

Attackers often use free email services like Gmail, Hotmail, and Yahoo to send phishing messages that are harder to detect. These platforms are widely trusted and have high deliverability, which makes it easier for malicious emails to land in your inbox.
It only takes a few minutes for an attacker to create a throwaway account. From there, they can spoof a display name to look like a coworker, vendor, or partner. Since free email addresses are often used in real conversations, the message may not seem out of place.
This tactic works because it blends in. A message might look clean, use a familiar name, and avoid anything that would trigger a filter. If you’re not paying close attention, it’s easy to miss the signs and respond without realizing the sender isn’t who they claim to be.
Rule Name & Severity
Last Updated
Author
Types, Tactics & Capabilities
Callback phishing: Zero-width character obfuscation from freemail sender
2d ago
Aug 5th, 2026
Sublime Security
VIP Impersonation via Google Group relay with suspicious indicators
2d ago
Aug 5th, 2026
Sublime Security
Brand impersonation: SiriusXM
3d ago
Aug 4th, 2026
Sublime Security
Spam: Default Microsoft Exchange Online sender domain (onmicrosoft.com)
4d ago
Aug 3rd, 2026
Sublime Security
COVID-19 themed fraud with sender and reply-to mismatch or compensation award
11d ago
Jul 27th, 2026
Sublime Security
BEC/Fraud: Penpal scam
11d ago
Jul 27th, 2026
Sublime Security
Attachment: Callback phishing solicitation via pdf file
11d ago
Jul 27th, 2026
Sublime Security
Impersonation: Suspected supplier impersonation with suspicious content
11d ago
Jul 27th, 2026
Sublime Security
Honorific greeting BEC attempt with sender and reply-to mismatch
11d ago
Jul 27th, 2026
Sublime Security
Impersonation: Employee name in subject with suspicious sender
28d ago
Jul 10th, 2026
Sublime Security
Attachment: Romance scam with image lure and advance-fee or suspicious link indicators
1mo ago
Jul 1st, 2026
Sublime Security
Request for Quote or Purchase (RFQ|RFP) with suspicious sender or recipient pattern
1mo ago
Jun 26th, 2026
Sublime Security
Suspicious request for financial information
1mo ago
Jun 25th, 2026
Sublime Security
Brand impersonation: Zoom via lookalike domain
1mo ago
Jun 22nd, 2026
Sublime Security
Employee impersonation: Payroll fraud
1mo ago
Jun 18th, 2026
Sublime Security
Evasion: Hidden content divs from freemail sender
1mo ago
Jun 17th, 2026
Sublime Security
Reconnaissance: Short generic greeting message
1mo ago
Jun 17th, 2026
Sublime Security
Link: Observed URL pattern with specific domain registrar
1mo ago
Jun 12th, 2026
Sublime Security
Attachment: Canva PDF with susupicious author metadata
2mo ago
Jun 5th, 2026
Sublime Security
BEC/Fraud: Job scam fake thread or plaintext pivot to freemail
2mo ago
Jun 5th, 2026
Sublime Security