Medium Severity
BEC/Fraud - Student loan callback phishing
Description
This rule detects phishing emails that attempt to engage the recipient by soliciting a callback under the guise of student loan forgiveness or assistance. The messages often come from free email providers, lack a proper HTML structure, and include suspicious indicators such as phone numbers embedded in the text. These emails typically contain language urging the recipient to respond or take immediate action, leveraging urgency around student loan repayment to entice engagement.
References
No references.
Sublime Security
Created Oct 4th, 2024 • Last updated Oct 4th, 2024
Feed Source
Sublime Core Feed
Source
type.inbound
// there is no HTML body
and body.html.raw is null
// but the current thread contains what's most likely an html tag
// (eg. <>'s' followed by a closing </> )
and regex.contains(body.current_thread.text, '<[^>]+>.*?</[^>]+>')
// and the body mentions student loans
and strings.icontains(body.current_thread.text, "Student Loan")
// sourced from a free mail provider
and sender.email.domain.root_domain in $free_email_providers
// contains a phone number
and (
regex.contains(strings.replace_confusables(body.current_thread.text),
'\+?(\d{1}.)?\(?\d{3}?\)?.\d{3}.?\d{4}'
)
or regex.contains(strings.replace_confusables(body.current_thread.text),
'\+\d{1,3}[0-9]{10}'
)
or // +12028001238
regex.contains(strings.replace_confusables(body.current_thread.text),
'[0-9]{3}\.[0-9]{3}\.[0-9]{4}'
)
or // 202.800.1238
regex.contains(strings.replace_confusables(body.current_thread.text),
'[0-9]{3}-[0-9]{3}-[0-9]{4}'
)
or // 202-800-1238
regex.contains(strings.replace_confusables(body.current_thread.text),
'\([0-9]{3}\)\s[0-9]{3}-[0-9]{4}'
)
or // (202) 800-1238
regex.contains(strings.replace_confusables(body.current_thread.text),
'\([0-9]{3}\)-[0-9]{3}-[0-9]{4}'
)
or // (202)-800-1238
regex.contains(strings.replace_confusables(body.current_thread.text),
'1 [0-9]{3} [0-9]{3} [0-9]{4}'
) // 8123456789
or regex.contains(strings.replace_confusables(body.current_thread.text),
'8\d{9}'
)
)
// contains a request
and any(ml.nlu_classifier(body.current_thread.text).entities,
.name == "request"
)
// sender is unsolicited
and not profile.by_sender().solicited
Playground
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