Detection rules › Sublime MQL

Service abuse: FlipHTML5 with attachment deception and credential theft language

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

Detects messages that reference attachments without including any, contain links to FlipHTML5 services, and exhibit high-confidence credential theft language patterns.

Threat classification

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

CategoryValues
Attack typesCredential Phishing
Tactics and techniquesSocial engineering, Free file host, Evasion

Event coverage

Rule body MQL

type.inbound
// messages contain wording to "see attached" but contains no attachments
and (
  regex.icontains(body.current_thread.text,
                  "attached|see.*attached|find.*attached|please{0,10}attached"
  )
  and length(attachments) == 0
)
// and the link goes to fliphtml5 and contains suspect "click me" language
and any(body.links, .href_url.domain.root_domain == "fliphtml5.com")
// and we have confidence its cred theft
and any(ml.nlu_classifier(body.current_thread.text).intents,
        .name == "cred_theft" and .confidence != "low"
)

Detection logic

Scope: inbound message.

Detects messages that reference attachments without including any, contain links to FlipHTML5 services, and exhibit high-confidence credential theft language patterns.

  1. inbound message
  2. all of:
    • body.current_thread.text matches 'attached|see.*attached|find.*attached|please{0,10}attached'
    • length(attachments) is 0
  3. any of body.links where:
    • .href_url.domain.root_domain is 'fliphtml5.com'
  4. any of ml.nlu_classifier(body.current_thread.text).intents where all hold:
    • .name is 'cred_theft'
    • .confidence is not 'low'

Inspects: body.current_thread.text, body.links, body.links[].href_url.domain.root_domain, type.inbound. Sensors: ml.nlu_classifier, regex.icontains.

Indicators matched (3)

FieldMatchValue
regex.icontainsregexattached|see.*attached|find.*attached|please{0,10}attached
body.links[].href_url.domain.root_domainequalsfliphtml5.com
ml.nlu_classifier(body.current_thread.text).intents[].nameequalscred_theft