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
Spam: Fake dating profile notification
10d ago
Mar 20th, 2026
Sublime Security
Spam: Sexually explicit content with emoji in subject from freemail provider
20d ago
Mar 10th, 2026
Sublime Security
BEC/Fraud: Romance scam
21d ago
Mar 9th, 2026
Sublime Security
Request for Quote or Purchase (RFQ|RFP) with suspicious sender or recipient pattern
21d ago
Mar 9th, 2026
Sublime Security
Brand impersonation: Zoom via lookalike domain
24d ago
Mar 6th, 2026
Sublime Security
BEC with unusual reply-to or return-path mismatch
27d ago
Mar 3rd, 2026
Sublime Security
Reconnaissance: Email address harvesting attempt
1mo ago
Feb 23rd, 2026
Sublime Security
Canva infrastructure abuse
1mo ago
Feb 6th, 2026
Sublime Security
ClickFunnels link infrastructure abuse
1mo ago
Feb 5th, 2026
Sublime Security
Impersonation: Executive using numbered local part
1mo ago
Jan 30th, 2026
Sublime Security
Reconnaissance: Hotel booking reply-to redirect
2mo ago
Jan 27th, 2026
Sublime Security
Reconnaissance: Short generic greeting message
2mo ago
Jan 27th, 2026
Sublime Security
Fake message thread - Untrusted sender with a mismatched freemail reply-to address
2mo ago
Jan 12th, 2026
Sublime Security
Message traversed multiple onmicrosoft.com tenants
2mo ago
Jan 12th, 2026
Sublime Security
Domain impersonation: Freemail reply-to local lookalike with financial request
2mo ago
Jan 12th, 2026
Sublime Security
Brand impersonation: Norton
2mo ago
Jan 12th, 2026
Sublime Security
Link: Apple App Store malicious ad manager themed apps from free email provider
2mo ago
Jan 12th, 2026
Sublime Security
Credential phishing: Engaging language and other indicators (untrusted sender)
2mo ago
Jan 12th, 2026
Sublime Security
Link: Invoice or receipt from freemail sender with customer service number
2mo ago
Jan 12th, 2026
@vector_sec
Spam: Default Microsoft Exchange Online sender domain (onmicrosoft.com)
2mo ago
Jan 12th, 2026
Sublime Security