Detection rules › Sublime MQL

Link: Direct link to gamma.app document with mode parameter

Severity
medium
Type
rule
Source
github.com/sublime-security/sublime-rules

Detects URLs linking to Gamma App presentation or document mode, which has been used to host malicious content due to its trusted domain status and presentation capabilities.

Threat classification

Sublime's own taxonomy (not MITRE ATT&CK).

CategoryValues
Attack typesCredential Phishing, Malware/Ransomware
Tactics and techniquesFree file host, Evasion

Event coverage

Rule body MQL

type.inbound
and length(body.links) < 10
and any(body.links,
        (
          .href_url.domain.root_domain == "gamma.app"
          or strings.icontains(.href_url.query_params, 'gamma.app')
          or strings.icontains(.href_url.query_params, 'gamma%2eapp')
          or strings.icontains(.href_url.query_params, 'gamma%252eapp')
        )
        and regex.icontains(.href_url.query_params, 'mode=(present|doc)')
)

Detection logic

Scope: inbound message.

Detects URLs linking to Gamma App presentation or document mode, which has been used to host malicious content due to its trusted domain status and presentation capabilities.

  1. inbound message
  2. length(body.links) < 10
  3. any of body.links where all hold:
    • any of:
      • .href_url.domain.root_domain is 'gamma.app'
      • .href_url.query_params contains 'gamma.app'
      • .href_url.query_params contains 'gamma%2eapp'
      • .href_url.query_params contains 'gamma%252eapp'
    • .href_url.query_params matches 'mode=(present|doc)'

Inspects: body.links, body.links[].href_url.domain.root_domain, body.links[].href_url.query_params, type.inbound. Sensors: regex.icontains, strings.icontains.

Indicators matched (5)

FieldMatchValue
body.links[].href_url.domain.root_domainequalsgamma.app
strings.icontainssubstringgamma.app
strings.icontainssubstringgamma%2eapp
strings.icontainssubstringgamma%252eapp
regex.icontainsregexmode=(present|doc)