Detection Method: Optical Character Recognition

OCR (Optical Character Recognition) helps systems read and analyze text in images, screenshots, and scanned documents. This method turns visual text into machine-readable content, allowing your security tools to catch things that would normally slip past text-based filters.
OCR can help you detect:
  • Phishing text hidden in images to bypass text-based filters
  • Suspicious language or instructions in scanned documents
  • QR codes with malicious links
  • Brand impersonation attempts using image-based logos or text
  • Requests for sensitive information disguised in images
For example, attackers often embed fake login prompts or instructions to call a "customer support" number in images. These tricks are designed to bypass traditional security filters, but OCR can extract and analyze the text to flag it as malicious before it reaches you.
Blog Posts
Hiding a $50,000 BEC financial fraud in a fake email thread · Blog · Sublime Security
Hiding a $50,000 BEC financial fraud in a fake email thread · 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
Detecting Credential Phishing using Deep Learning + MQL · Blog · Sublime Security
Detecting Credential Phishing using Deep Learning + MQL · Blog · Sublime Security
Attack Types (6):
Credential Phishing
Extortion
BEC/Fraud
Callback Phishing
Spam
Malware/Ransomware
Tactics & Techniques (15):
Evasion
Free file host
Social engineering
Image as content
Impersonation: Brand
Free subdomain host
PDF
Impersonation: VIP
Out of band pivot
Open redirect
Macros
Free email provider
QR code
Spoofing
Encryption
Rule Name & Severity
Last Updated
Author
Types, Tactics & Capabilities
Link: Figma design deck with credential theft language
13h ago
Mar 4th, 2026
Sublime Security
Credential Phishing
Evasion
Free file host
Social engineering
Natural Language Understanding
Computer Vision
Optical Character Recognition
URL analysis
URL screenshot
Sender analysis
/feeds/core/detection-rules/link-figma-design-deck-with-credential-theft-language-87601924
Cloud storage impersonation with credential theft indicators
13d ago
Feb 20th, 2026
Sublime Security
Credential Phishing
Free file host
Image as content
Impersonation: Brand
Social engineering
Computer Vision
Content analysis
Header analysis
Natural Language Understanding
Optical Character Recognition
Sender analysis
URL analysis
/feeds/core/detection-rules/cloud-storage-impersonation-with-credential-theft-indicators-4c20f72c
Impersonation: Recipient organization in sender display name with credential theft image
16d ago
Feb 17th, 2026
Sublime Security
Credential Phishing
Image as content
Impersonation: Brand
Social engineering
Computer Vision
Content analysis
File analysis
Natural Language Understanding
Optical Character Recognition
Sender analysis
/feeds/core/detection-rules/impersonation-recipient-organization-in-sender-display-name-with-credential-theft-image-6abfb20e
Brand impersonation: TikTok
21d ago
Feb 12th, 2026
Sublime Security
Credential Phishing
Impersonation: Brand
Social engineering
Computer Vision
Content analysis
Header analysis
Natural Language Understanding
Optical Character Recognition
Sender analysis
/feeds/core/detection-rules/brand-impersonation-tiktok-aaacc8b7
Brand impersonation: Fake Fax
28d ago
Feb 5th, 2026
Sublime Security
Credential Phishing
Impersonation: Brand
Image as content
Free file host
Free subdomain host
Social engineering
Computer Vision
Content analysis
Optical Character Recognition
Sender analysis
URL analysis
/feeds/core/detection-rules/brand-impersonation-fake-fax-2a96b90a
Attachment: Legal themed message or PDF with suspicious indicators
28d ago
Feb 5th, 2026
Sublime Security
Credential Phishing
Extortion
BEC/Fraud
Evasion
PDF
Social engineering
Content analysis
File analysis
Natural Language Understanding
Optical Character Recognition
URL analysis
Whois
Header analysis
Exif analysis
/feeds/core/detection-rules/attachment-legal-themed-message-or-pdf-with-suspicious-indicators-19133301
Attachment: Office file with document sharing and browser instruction lures
1mo ago
Jan 29th, 2026
Sublime Security
Credential Phishing
Social engineering
Evasion
Archive analysis
File analysis
Macro analysis
Optical Character Recognition
Content analysis
/feeds/core/detection-rules/attachment-office-file-with-document-sharing-and-browser-instruction-lures-b1250a4b
Link: Microsoft Dynamics 365 form phishing
1mo ago
Jan 27th, 2026
Sublime Security
Credential Phishing
Evasion
Content analysis
File analysis
Optical Character Recognition
Natural Language Understanding
URL analysis
URL screenshot
/feeds/core/detection-rules/link-microsoft-dynamics-365-form-phishing-f72b9085
Attachment: Fake lawyer & sports agent identities
1mo ago
Jan 26th, 2026
Sublime Security
BEC/Fraud
Impersonation: VIP
Social engineering
Content analysis
Exif analysis
File analysis
Optical Character Recognition
/feeds/core/detection-rules/attachment-fake-lawyer-and-sports-agent-identities-7d3a2478
Callback phishing in body or attachment (untrusted sender)
1mo ago
Jan 22nd, 2026
Sublime Security
Callback Phishing
Out of band pivot
Social engineering
Content analysis
File analysis
Optical Character Recognition
Natural Language Understanding
Sender analysis
/feeds/core/detection-rules/callback-phishing-in-body-or-attachment-untrusted-sender-b93c6f94
Attachment: Invoice and W-9 PDFs with suspicious creators
1mo ago
Jan 21st, 2026
Sublime Security
BEC/Fraud
PDF
Social engineering
Impersonation: Brand
File analysis
Optical Character Recognition
Exif analysis
Content analysis
/feeds/core/detection-rules/attachment-invoice-and-w-9-pdfs-with-suspicious-creators-305d6e32
Brand impersonation: SendGrid
1mo ago
Jan 12th, 2026
Sublime Security
BEC/Fraud
Credential Phishing
Spam
Impersonation: Brand
Social engineering
Content analysis
Header analysis
Natural Language Understanding
Optical Character Recognition
Sender analysis
/feeds/core/detection-rules/brand-impersonation-sendgrid-d800124f
Open Redirect: Google domain with /url path and suspicious indicators
1mo ago
Jan 12th, 2026
Sublime Security
Credential Phishing
Evasion
Open redirect
Computer Vision
Content analysis
File analysis
Header analysis
Natural Language Understanding
Optical Character Recognition
Sender analysis
URL analysis
/feeds/core/detection-rules/open-redirect-google-domain-with-url-path-and-suspicious-indicators-fc5adf74
Link to auto-downloaded file with Google Drive branding
1mo ago
Jan 12th, 2026
Sublime Security
Malware/Ransomware
Impersonation: Brand
Social engineering
Content analysis
File analysis
Optical Character Recognition
URL analysis
URL screenshot
/feeds/core/detection-rules/link-to-auto-downloaded-file-with-google-drive-branding-4b5343be
Brand impersonation: Microsoft with low reputation links
1mo ago
Jan 12th, 2026
Sublime Security
Credential Phishing
Free file host
Image as content
Impersonation: Brand
Social engineering
Computer Vision
Content analysis
File analysis
Header analysis
Natural Language Understanding
Optical Character Recognition
Sender analysis
URL analysis
/feeds/core/detection-rules/brand-impersonation-microsoft-with-low-reputation-links-b59201b6
Link: Multistage landing - Abused Adobe Acrobat hosted PDF
1mo ago
Jan 12th, 2026
Sublime Security
Credential Phishing
Impersonation: Brand
Social engineering
Computer Vision
Optical Character Recognition
URL analysis
Header analysis
Sender analysis
/feeds/core/detection-rules/link-multistage-landing-abused-adobe-acrobat-hosted-pdf-609081ef
Link: Multistage landing - Scribd document
1mo ago
Jan 12th, 2026
Sublime Security
Credential Phishing
Evasion
Social engineering
Impersonation: Brand
Free file host
URL analysis
HTML analysis
Natural Language Understanding
Computer Vision
Optical Character Recognition
URL screenshot
/feeds/core/detection-rules/link-multistage-landing-scribd-document-afa9807d
Suspicious recipient pattern and language with low reputation link to login
1mo ago
Jan 12th, 2026
Sublime Security
Credential Phishing
Social engineering
Computer Vision
Content analysis
Header analysis
Natural Language Understanding
Optical Character Recognition
Sender analysis
URL analysis
URL screenshot
/feeds/core/detection-rules/suspicious-recipient-pattern-and-language-with-low-reputation-link-to-login-a8ea0402
Attachment: Microsoft 365 credential phishing
1mo ago
Jan 12th, 2026
Sublime Security
Credential Phishing
Impersonation: Brand
Social engineering
Content analysis
File analysis
Header analysis
Optical Character Recognition
Sender analysis
/feeds/core/detection-rules/attachment-microsoft-365-credential-phishing-edce0229
Attachment: PDF with credential theft language and link to a free subdomain (unsolicited)
1mo ago
Jan 12th, 2026
Sublime Security
Credential Phishing
Free subdomain host
PDF
Social engineering
File analysis
Natural Language Understanding
Optical Character Recognition
Sender analysis
URL analysis
/feeds/core/detection-rules/attachment-pdf-with-credential-theft-language-and-link-to-a-free-subdomain-unsolicited-90f4ef4e
Page 1 of 4