sublimemediumRule

Brand impersonation: KnowBe4

Impersonation of KnowBe4.

MITRE ATT&CK

T1566 T1566.001 T1566.002 T1598 T1598.003 T1583.001

initial-access

Detection Query

type.inbound
and (
  sender.display_name =~ 'KnowBe4'
  or strings.ilevenshtein(sender.display_name, 'KnowBe4') <= 1
  or strings.icontains(sender.email.domain.domain, '*KnowBe4*')
)
and (
  sender.email.domain.root_domain not in ('knowbe4.com')
  or (
    sender.email.domain.root_domain in ('knowbe4.com')
    and not headers.auth_summary.dmarc.pass
  )
)

// negate highly trusted sender domains unless they fail DMARC authentication
and (
  (
    sender.email.domain.root_domain in $high_trust_sender_root_domains
    and not headers.auth_summary.dmarc.pass
  )
  or sender.email.domain.root_domain not in $high_trust_sender_root_domains
)

Data Sources

Email MessagesEmail HeadersEmail Attachments

Platforms

Raw Content

name: "Brand impersonation: KnowBe4"
description: "Impersonation of KnowBe4."
type: "rule"
severity: "medium"
source: |
  type.inbound
  and (
    sender.display_name =~ 'KnowBe4'
    or strings.ilevenshtein(sender.display_name, 'KnowBe4') <= 1
    or strings.icontains(sender.email.domain.domain, '*KnowBe4*')
  )
  and (
    sender.email.domain.root_domain not in ('knowbe4.com')
    or (
      sender.email.domain.root_domain in ('knowbe4.com')
      and not headers.auth_summary.dmarc.pass
    )
  )
  
  // negate highly trusted sender domains unless they fail DMARC authentication
  and (
    (
      sender.email.domain.root_domain in $high_trust_sender_root_domains
      and not headers.auth_summary.dmarc.pass
    )
    or sender.email.domain.root_domain not in $high_trust_sender_root_domains
  )
attack_types:
  - "Credential Phishing"
  - "Spam"
tactics_and_techniques:
  - "Free email provider"
  - "Impersonation: Brand"
  - "Lookalike domain"
  - "Social engineering"
detection_methods:
  - "Computer Vision"
  - "Header analysis"
  - "Sender analysis"
id: "7c798386-fd25-5890-83b3-85187adbfc44"