Detection Method: Natural Language Understanding

Natural Language Understanding (NLU) uses machine learning algorithms to analyze and interpret message content, helping systems detect subtle signs of malicious intent. Instead of just matching keywords, NLU looks at the context, tone, urgency, and intent behind the message.
NLU can help you detect:
  • Urgent language commonly used in BEC attacks impersonating executives or departments
  • Credential theft attempts disguised as legitimate service notifications
  • Extortion or blackmail tactics used in intimidation campaigns
  • Financial terms typically found in payment fraud or invoice scams
  • Deceptive job offers designed to steal sensitive information
For example, NLU can identify when an email uses urgent language ("immediate attention required") combined with financial requests ("wire transfer") and impersonation, which are common tactics in BEC attacks.
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
Callback phishing via invoice abuse and distribution list relays · Blog · Sublime Security
Callback phishing via invoice abuse and distribution list relays · Blog · Sublime Security
B2B freight-forwarding scams on the rise to evade financial fraud crackdowns · Blog · Sublime Security
B2B freight-forwarding scams on the rise to evade financial fraud crackdowns · Blog · Sublime Security
Hidden credential phishing within EML attachments · Blog · Sublime Security
Hidden credential phishing within EML attachments · Blog · Sublime Security
Adversarial ML: Extortion via LLM Manipulation Tactics · Blog · Sublime Security
Adversarial ML: Extortion via LLM Manipulation Tactics · Blog · Sublime Security
Combating GenAI Email Attacks with BERT LLM · Blog · Sublime Security
Combating GenAI Email Attacks with BERT LLM · Blog · Sublime Security
Payroll Fraud via LLM-Generated Emails · Blog · Sublime Security
Payroll Fraud via LLM-Generated Emails · Blog · Sublime Security
Fake invoice used to conduct $16,800 BEC attempt · Blog · Sublime Security
Fake invoice used to conduct $16,800 BEC attempt · Blog · Sublime Security
QR Code Phishing: Decoding Hidden Threats · Blog · Sublime Security
QR Code Phishing: Decoding Hidden Threats · 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):
Extortion
Credential Phishing
BEC/Fraud
Callback Phishing
Spam
Malware/Ransomware
Tactics & Techniques (20):
Social engineering
Spoofing
Impersonation: Brand
Impersonation: Employee
Out of band pivot
Evasion
Free file host
Free subdomain host
Free email provider
QR code
PDF
Image as content
Lookalike domain
Encryption
Scripting
Impersonation: VIP
Open redirect
Macros
IPFS
HTML smuggling
Rule Name & Severity
Last Updated
Author
Types, Tactics & Capabilities
Extortion / sextortion (untrusted sender)
14d ago
Dec 19th, 2025
Sublime Security
Extortion
Social engineering
Spoofing
Content analysis
Header analysis
Natural Language Understanding
Sender analysis
/feeds/core/detection-rules/extortion-sextortion-untrusted-sender-265913eb
Fake voicemail notification (untrusted sender)
15d ago
Dec 18th, 2025
Sublime Security
Credential Phishing
Social engineering
Content analysis
Natural Language Understanding
Sender analysis
URL analysis
/feeds/core/detection-rules/fake-voicemail-notification-untrusted-sender-74ba7787
Xero invoice abuse
16d ago
Dec 17th, 2025
Sublime Security
BEC/Fraud
Credential Phishing
Impersonation: Brand
Impersonation: Employee
Social engineering
Natural Language Understanding
Content analysis
Sender analysis
/feeds/core/detection-rules/xero-invoice-abuse-6538c600
Callback phishing via Microsoft comment
17d ago
Dec 16th, 2025
Sublime Security
Callback Phishing
Impersonation: Brand
Out of band pivot
Social engineering
Content analysis
Header analysis
Natural Language Understanding
Sender analysis
/feeds/core/detection-rules/callback-phishing-via-microsoft-comment-8346c7b9
Salesforce infrastructure abuse
17d ago
Dec 16th, 2025
Sublime Security
Credential Phishing
Evasion
Social engineering
Content analysis
Header analysis
Natural Language Understanding
URL analysis
/feeds/core/detection-rules/salesforce-infrastructure-abuse-78a77c70
Business Email Compromise: Request for mobile number via reply thread hijacking
18d ago
Dec 15th, 2025
Sublime Security
BEC/Fraud
Social engineering
Content analysis
Natural Language Understanding
Sender analysis
/feeds/core/detection-rules/business-email-compromise-request-for-mobile-number-via-reply-thread-hijacking-0282f346
Deceptive Dropbox mention
18d ago
Dec 15th, 2025
Sublime Security
Credential Phishing
Impersonation: Brand
Free file host
Free subdomain host
Social engineering
Header analysis
Content analysis
Natural Language Understanding
Sender analysis
URL analysis
/feeds/core/detection-rules/deceptive-dropbox-mention-58a107bc
Credential phishing: Engaging language and other indicators (untrusted sender)
21d ago
Dec 12th, 2025
Sublime Security
Credential Phishing
Free email provider
Social engineering
Content analysis
Header analysis
Natural Language Understanding
Sender analysis
URL analysis
/feeds/core/detection-rules/credential-phishing-engaging-language-and-other-indicators-untrusted-sender-c2bc8ca2
Credential phishing: Suspicious subject with urgent financial request and link
21d ago
Dec 12th, 2025
Sublime Security
Credential Phishing
Impersonation: Brand
Social engineering
Content analysis
Header analysis
Natural Language Understanding
Sender analysis
/feeds/core/detection-rules/credential-phishing-suspicious-subject-with-urgent-financial-request-and-link-056464f4
Brand impersonation: Wise
21d ago
Dec 12th, 2025
Sublime Security
Credential Phishing
Impersonation: Brand
Social engineering
Content analysis
Natural Language Understanding
Sender analysis
/feeds/core/detection-rules/brand-impersonation-wise-01480f95
QR Code with suspicious indicators
21d ago
Dec 12th, 2025
Sublime Security
Credential Phishing
QR code
Social engineering
Content analysis
Header analysis
Computer Vision
Natural Language Understanding
QR code analysis
Sender analysis
URL analysis
/feeds/core/detection-rules/qr-code-with-suspicious-indicators-04f5c34f
Link: Self-sender with sender org in subject and credential theft indicator
22d ago
Dec 11th, 2025
Sublime Security
Credential Phishing
Social engineering
Evasion
Natural Language Understanding
Content analysis
Sender analysis
URL analysis
Header analysis
/feeds/core/detection-rules/link-self-sender-with-sender-org-in-subject-and-credential-theft-indicator-bfa9aa08
Scam: Piano giveaway
22d ago
Dec 11th, 2025
Sublime Security
BEC/Fraud
Free email provider
Content analysis
Natural Language Understanding
Sender analysis
/feeds/core/detection-rules/scam-piano-giveaway-1a91a203
Spam: Website errors solicitation
22d ago
Dec 11th, 2025
Sublime Security
Spam
Content analysis
Sender analysis
Natural Language Understanding
/feeds/core/detection-rules/spam-website-errors-solicitation-122ea794
Attachment: Compensation review lure with QR code
23d ago
Dec 10th, 2025
Sublime Security
Credential Phishing
PDF
QR code
Social engineering
File analysis
Optical Character Recognition
QR code analysis
Natural Language Understanding
Sender analysis
Header analysis
/feeds/core/detection-rules/attachment-compensation-review-lure-with-qr-code-9fd8185c
Brand impersonation: Microsoft with low reputation links
23d ago
Dec 10th, 2025
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
Fake thread with suspicious indicators
24d ago
Dec 9th, 2025
Sublime Security
BEC/Fraud
Credential Phishing
Spam
Evasion
Social engineering
Content analysis
Header analysis
Natural Language Understanding
Sender analysis
/feeds/core/detection-rules/fake-thread-with-suspicious-indicators-c2e18a57
Credential phishing: Generic document sharing
25d ago
Dec 8th, 2025
Sublime Security
Credential Phishing
BEC/Fraud
Social engineering
Evasion
Impersonation: Employee
Content analysis
Natural Language Understanding
URL analysis
Sender analysis
/feeds/core/detection-rules/credential-phishing-generic-document-sharing-9f0e1d2c
Link: Microsoft Dynamics 365 form phishing
28d ago
Dec 5th, 2025
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
Service abuse: Sendgrid credential theft with personalized request targeting single recipient
29d ago
Dec 4th, 2025
Sublime Security
Credential Phishing
Social engineering
Header analysis
Natural Language Understanding
Sender analysis
Content analysis
/feeds/core/detection-rules/service-abuse-sendgrid-credential-theft-with-personalized-request-targeting-single-recipient-b9680da1
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