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):
Credential Phishing
BEC/Fraud
Spam
Malware/Ransomware
Callback Phishing
Extortion
Tactics & Techniques (20):
Evasion
Free file host
Social engineering
Impersonation: Brand
Free email provider
Impersonation: VIP
Encryption
PDF
Free subdomain host
Spoofing
Image as content
Impersonation: Employee
Out of band pivot
Lookalike domain
QR code
Macros
Open redirect
Scripting
IPFS
HTML smuggling
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
Brand Impersonation: Disney
17h ago
Mar 4th, 2026
Sublime Security
Credential Phishing
Impersonation: Brand
Social engineering
Computer Vision
Natural Language Understanding
Content analysis
Header analysis
Sender analysis
/feeds/core/detection-rules/brand-impersonation-disney-bf90b8fb
BEC with unusual reply-to or return-path mismatch
2d ago
Mar 3rd, 2026
Sublime Security
BEC/Fraud
Evasion
Free email provider
Social engineering
Content analysis
Header analysis
Natural Language Understanding
Sender analysis
/feeds/core/detection-rules/bec-with-unusual-reply-to-or-return-path-mismatch-83e5e2df
Link: Google Forms link with credential theft language
3d ago
Mar 2nd, 2026
Sublime Security
Credential Phishing
Social engineering
Natural Language Understanding
Sender analysis
URL analysis
/feeds/core/detection-rules/link-google-forms-link-with-credential-theft-language-0cad40e2
VIP impersonation with w2 request with reply-to mismatch
6d ago
Feb 27th, 2026
Sublime Security
BEC/Fraud
Impersonation: VIP
Content analysis
Header analysis
Natural Language Understanding
/feeds/core/detection-rules/vip-impersonation-with-w2-request-with-reply-to-mismatch-e7e73fad
Attachment: Encrypted PDF with credential theft body
7d ago
Feb 26th, 2026
Sublime Security
Credential Phishing
Encryption
Evasion
PDF
Social engineering
Content analysis
Exif analysis
File analysis
Natural Language Understanding
Sender analysis
/feeds/core/detection-rules/attachment-encrypted-pdf-with-credential-theft-body-c9596c9a
Credential theft with 'safe content' deception and social engineering topics
8d ago
Feb 25th, 2026
Sublime Security
Credential Phishing
Social engineering
Evasion
Content analysis
Natural Language Understanding
/feeds/core/detection-rules/credential-theft-with-safe-content-deception-and-social-engineering-topics-22ceee0d
Spam: Sendersrv.com with financial communications and unsubscribe language
9d ago
Feb 24th, 2026
Sublime Security
Spam
Evasion
Social engineering
Header analysis
Content analysis
Natural Language Understanding
Sender analysis
/feeds/core/detection-rules/spam-sendersrvcom-with-financial-communications-and-unsubscribe-language-69570820
Link: Free file hosting with undisclosed recipients
10d ago
Feb 23rd, 2026
Sublime Security
Credential Phishing
Malware/Ransomware
Free file host
Free subdomain host
Evasion
Header analysis
URL analysis
Sender analysis
Natural Language Understanding
/feeds/core/detection-rules/link-free-file-hosting-with-undisclosed-recipients-b6281306
Brand impersonation: Survey request with credential theft indicators
13d ago
Feb 20th, 2026
Sublime Security
Credential Phishing
Social engineering
Impersonation: Brand
Spoofing
Content analysis
Header analysis
Natural Language Understanding
Sender analysis
/feeds/core/detection-rules/brand-impersonation-survey-request-with-credential-theft-indicators-ea1c0e09
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
Credential phishing: Generic document sharing
19d ago
Feb 14th, 2026
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
Brand impersonation: USPS
20d ago
Feb 13th, 2026
Sublime Security
Credential Phishing
Image as content
Impersonation: Brand
Social engineering
Computer Vision
Content analysis
Natural Language Understanding
Sender analysis
/feeds/core/detection-rules/brand-impersonation-usps-28b9130a
Link: Credential theft with invisible Unicode character in page title from unsolicited sender
20d ago
Feb 13th, 2026
Sublime Security
Credential Phishing
Evasion
Social engineering
Natural Language Understanding
Content analysis
HTML analysis
URL analysis
URL screenshot
/feeds/core/detection-rules/link-credential-theft-with-invisible-unicode-character-in-page-title-from-unsolicited-sender-5fe14d53
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
Link: PDF filename impersonation with credential theft language
21d ago
Feb 12th, 2026
Sublime Security
Credential Phishing
Social engineering
Evasion
PDF
Content analysis
Natural Language Understanding
Header analysis
Sender analysis
URL analysis
/feeds/core/detection-rules/link-pdf-filename-impersonation-with-credential-theft-language-05931513
Brand impersonation: Navan
24d ago
Feb 9th, 2026
Sublime Security
Credential Phishing
Impersonation: Brand
Social engineering
Spoofing
Sender analysis
Natural Language Understanding
URL analysis
Content analysis
/feeds/core/detection-rules/brand-impersonation-navan-3573e9a8
Link: URL shortener with copy-paste instructions and credential theft language
27d ago
Feb 6th, 2026
Sublime Security
Credential Phishing
Evasion
Social engineering
Content analysis
Natural Language Understanding
URL analysis
/feeds/core/detection-rules/link-url-shortener-with-copy-paste-instructions-and-credential-theft-language-a0a2c573
Service abuse: Apple TestFlight with suspicious developer reference
27d ago
Feb 6th, 2026
Sublime Security
Spam
Social engineering
Content analysis
HTML analysis
Natural Language Understanding
Sender analysis
URL analysis
/feeds/core/detection-rules/service-abuse-apple-testflight-with-suspicious-developer-reference-e7ea0ee0
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