Detection Method: HTML analysis

HTML analysis looks at the HTML code in emails, web pages, or attachments to spot potentially malicious elements or deceptive structures. It examines both what’s visible and hidden in the HTML to uncover tactics often used in phishing or malware attacks.
HTML analysis can help you detect:
  • Hidden scripts or iframes that might run harmful code
  • Obfuscated JavaScript designed to avoid detection
  • Misleading hyperlinks where the displayed text doesn’t match the real URL
  • Forms made to steal credentials or sensitive data
  • Suspicious HTML comments with hidden instructions
  • CSS tricks used to hide malicious content
For example, phishing emails often use HTML to replicate trusted login pages. HTML analysis can catch the hidden forms and scripts trying to steal your credentials.
Blog Posts
Talking phish over turkey · Blog · Sublime Security
Talking phish over turkey · Blog · Sublime Security
Living Off the Land: Credential Phishing via Docusign abuse · Blog · Sublime Security
Living Off the Land: Credential Phishing via Docusign abuse · Blog · Sublime Security
Call Me Maybe? The Rise of Callback Phishing Emails · Blog · Sublime Security
Call Me Maybe? The Rise of Callback Phishing Emails · Blog · Sublime Security
Attack Types (6):
Credential Phishing
Spam
BEC/Fraud
Malware/Ransomware
Callback Phishing
Extortion
Tactics & Techniques (23):
Evasion
Social engineering
Spoofing
Free subdomain host
Free email provider
Free file host
HTML smuggling
Impersonation: Brand
Image as content
Open redirect
Out of band pivot
Scripting
ICS Phishing
Exploit
PDF
Impersonation: VIP
Lookalike domain
Credential Phishing
Encryption
HTML injection
Impersonation: Employee
OneNote
ISO
Rule Name & Severity
Last Updated
Author
Types, Tactics & Capabilities
Body: Fake secure email portal with HTML obfuscation
5d ago
Jun 18th, 2026
Sublime Security
Credential Phishing
Evasion
Social engineering
Spoofing
Content analysis
HTML analysis
URL analysis
Sender analysis
Threat intelligence
Service abuse: Google Firebase sender address with suspicious content
5d ago
Jun 18th, 2026
Sublime Security
Spam
Credential Phishing
Free subdomain host
Social engineering
Content analysis
Header analysis
HTML analysis
Natural Language Understanding
Sender analysis
URL analysis
Whois
Evasion: Hidden content divs from freemail sender
6d ago
Jun 17th, 2026
Sublime Security
Credential Phishing
Evasion
Free email provider
HTML analysis
Content analysis
Sender analysis
Self-impersonation: Sender matches recipient with bolded name and suspicious link
7d ago
Jun 16th, 2026
Sublime Security
Credential Phishing
Evasion
Social engineering
Header analysis
HTML analysis
Sender analysis
Impersonation: Fake product discount promotion
7d ago
Jun 16th, 2026
Sublime Security
BEC/Fraud
Social engineering
Free file host
Content analysis
HTML analysis
URL analysis
HTML content with print styling and credential theft language
7d ago
Jun 16th, 2026
Sublime Security
Credential Phishing
Evasion
HTML smuggling
Social engineering
Content analysis
HTML analysis
Natural Language Understanding
Body: Yellow highlighted text markers
7d ago
Jun 16th, 2026
Sublime Security
Credential Phishing
BEC/Fraud
Evasion
HTML analysis
Content analysis
Link: Credential harvesting with excess padding evasion
8d ago
Jun 15th, 2026
Sublime Security
Credential Phishing
Evasion
Social engineering
Content analysis
HTML analysis
Exif analysis
URL screenshot
Brand impersonation: Adobe Sign with suspicious indicators
13d ago
Jun 10th, 2026
Sublime Security
Credential Phishing
Impersonation: Brand
Social engineering
Content analysis
Header analysis
HTML analysis
Sender analysis
Attachment: EML file contains HTML attachment with login portal indicators
18d ago
Jun 5th, 2026
Sublime Security
Credential Phishing
Evasion
HTML smuggling
Content analysis
File analysis
Header analysis
HTML analysis
Javascript analysis
Sender analysis
Brand impersonation: Fake DocuSign HTML table not linking to DocuSign domains
18d ago
Jun 5th, 2026
Sublime Security
Credential Phishing
Impersonation: Brand
Social engineering
Content analysis
HTML analysis
Header analysis
Sender analysis
URL analysis
Brand impersonation: Zoom
18d ago
Jun 5th, 2026
Sublime Security
Credential Phishing
Impersonation: Brand
Social engineering
Evasion
Computer Vision
Content analysis
HTML analysis
Natural Language Understanding
URL analysis
Credential phishing: Suspicious e-sign agreement document notification
18d ago
Jun 5th, 2026
Sublime Security
Credential Phishing
Social engineering
Content analysis
Header analysis
HTML analysis
URL analysis
Sender analysis
Link: Self-sent PDF lure with subject correlation
19d ago
Jun 4th, 2026
Sublime Security
BEC/Fraud
Credential Phishing
Social engineering
Evasion
Header analysis
HTML analysis
Sender analysis
Content analysis
Body: HTML whitespace stuffing with short initial message
25d ago
May 29th, 2026
Sublime Security
Credential Phishing
Evasion
Social engineering
Content analysis
HTML analysis
Header analysis
Brand impersonation: Figma with malicious document access overlay
27d ago
May 27th, 2026
Sublime Security
Credential Phishing
Impersonation: Brand
Social engineering
Image as content
Sender analysis
HTML analysis
URL screenshot
Optical Character Recognition
URL analysis
Image as content with a link to an open redirect
28d ago
May 26th, 2026
Sublime Security
Credential Phishing
Malware/Ransomware
Evasion
Image as content
Open redirect
Social engineering
Content analysis
HTML analysis
URL analysis
Service abuse: Amazon invitation with suspected callback phishing
1mo ago
May 22nd, 2026
Sublime Security
Callback Phishing
Out of band pivot
Social engineering
Content analysis
HTML analysis
Sender analysis
Brand impersonation: Paperless Post
1mo ago
May 18th, 2026
Sublime Security
Credential Phishing
Malware/Ransomware
Impersonation: Brand
Content analysis
Header analysis
HTML analysis
Sender analysis
URL analysis
Attachment: Embedded VBScript in MHT file
1mo ago
May 14th, 2026
Sublime Security
Malware/Ransomware
Evasion
Scripting
Archive analysis
File analysis
HTML analysis
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