Detection rules › Sublime MQL
Callback phishing via Intuit service abuse
Callback phishing campaigns have been observed abusing Intuit Quickbooks services to send fraudulent invoices with callback phishing contents.
Threat classification
Sublime's own taxonomy (not MITRE ATT&CK).
| Category | Values |
|---|---|
| Attack types | Callback Phishing |
| Tactics and techniques | Evasion, Free email provider, Impersonation: Brand, Social engineering |
Event coverage
Rule body MQL
type.inbound
// Legitimate Intuit sending infratructure
and (
sender.email.domain.root_domain in ('intuit.com', 'intuit.co.uk')
// check for SPF or DMARC passed
and (headers.auth_summary.spf.pass or headers.auth_summary.dmarc.pass)
)
and (
// Callback Phishing in body (brand names required)
(
length(attachments) == 0
// brand names are required.
and regex.icontains(strings.replace_confusables(body.current_thread.text),
(
"mcafee|norton|geek.{0,5}squad|paypal|ebay|symantec|best buy|lifelock"
)
)
and 3 of (
strings.ilike(body.current_thread.text, '*purchase*'),
strings.ilike(body.current_thread.text, '*payment*'),
strings.ilike(body.current_thread.text, '*transaction*'),
strings.ilike(body.current_thread.text, '*subscription*'),
strings.ilike(body.current_thread.text, '*antivirus*'),
strings.ilike(body.current_thread.text, '*order*'),
strings.ilike(body.current_thread.text, '*support*'),
strings.ilike(body.current_thread.text, '*help line*'),
strings.ilike(body.current_thread.text, '*receipt*'),
strings.ilike(body.current_thread.text, '*invoice*'),
strings.ilike(body.current_thread.text, '*call*'),
strings.ilike(body.current_thread.text, '*cancel*'),
strings.ilike(body.current_thread.text, '*renew*'),
strings.ilike(body.current_thread.text, '*refund*')
)
// phone number regex
and any([body.current_thread.text, subject.subject],
regex.icontains(., '\b\+?(\d{1}.)?\(?\d{3}?\)?.\d{3}.?\d{4}\b')
)
)
// Callback Phishing in the "billtoContent"
or
// icontains a phone number
(
regex.icontains(strings.replace_confusables(body.html.inner_text),
'(?:Sold|Bill)[\s\xa0]To(?:\:\s+|\n)[^\n]+\+?(\d{1}.)?\(?\d{3}?\)?.\d{3}.?\d{4}.*\n'
)
or regex.icontains(strings.replace_confusables(body.html.inner_text),
'(?:Sold|Bill)[\s\xa0]To(?:\:\s+|\n)[^\n]+\+\d{1,3}[ilo0-9]{10}.*\n'
)
// +12028001238
or regex.icontains(strings.replace_confusables(body.html.inner_text),
'(?:Sold|Bill)[\s\xa0]To(?:\:\s+|\n)[^\n]+[ilo0-9]{3}\.[ilo0-9]{3}\.[ilo0-9]{4}.*\n'
)
// 202-800-1238
or regex.icontains(strings.replace_confusables(body.html.inner_text),
'(?:Sold|Bill)[\s\xa0]To(?:\:\s+|\n)[^\n]+[ilo0-9]{3}-[ilo0-9]{3}-[ilo0-9]{4}.*\n'
)
// (202) 800-1238
or regex.icontains(strings.replace_confusables(body.html.inner_text),
'(?:Sold|Bill)[\s\xa0]To(?:\:\s+|\n)[^\n]+\([ilo0-9]{3}\)[\s-]+[ilo0-9]{3}[\s-]+[ilo0-9]{4}.*\n'
)
// (202)-800-1238
or regex.icontains(strings.replace_confusables(body.html.inner_text),
'(?:Sold|Bill)[\s\xa0]To(?:\:\s+|\n)[^\n]+\([ilo0-9]{3}\)-[ilo0-9]{3}-[ilo0-9]{4}.*\n'
)
// 202 800 1238
or regex.icontains(strings.replace_confusables(body.html.inner_text),
'(?:Sold|Bill)[\s\xa0]To(?:\:\s+|\n)[^\n]+1\s?[ilo0-9]{3} [ilo0-9]{3} [ilo0-9]{4}.*\n'
) // 8123456789
or (
regex.icontains(strings.replace_confusables(body.html.inner_text),
'(?:Sold|Bill)[\s\xa0]To(?:\:\s+|\n)[^\n]+8\d{9}.*\n'
)
and regex.icontains(strings.replace_confusables(body.html.inner_text),
'\+1'
)
)
)
// all attachments are PDFs with callback phishing indicators Brands Required
or (
length(attachments) < 3
and all(attachments, .file_extension == "pdf")
// the attachment is a pdf with 1 page, and at least 60 ocr chars
and any(attachments,
(
.file_extension == "pdf"
and any(file.explode(.), .scan.exiftool.page_count < 3)
and any(file.explode(.), length(.scan.ocr.raw) > 60)
// 4 of the following strings are found
and (
any(file.explode(.),
4 of (
strings.icontains(.scan.ocr.raw, "purchase"),
strings.icontains(.scan.ocr.raw, "payment"),
strings.icontains(.scan.ocr.raw, "transaction"),
strings.icontains(.scan.ocr.raw, "subscription"),
strings.icontains(.scan.ocr.raw, "antivirus"),
strings.icontains(.scan.ocr.raw, "order"),
strings.icontains(.scan.ocr.raw, "support"),
strings.icontains(.scan.ocr.raw, "help line"),
strings.icontains(.scan.ocr.raw, "receipt"),
strings.icontains(.scan.ocr.raw, "invoice"),
strings.icontains(.scan.ocr.raw, "call"),
strings.icontains(.scan.ocr.raw, "helpdesk"),
strings.icontains(.scan.ocr.raw, "cancel"),
strings.icontains(.scan.ocr.raw, "renew"),
strings.icontains(.scan.ocr.raw, "refund"),
strings.icontains(.scan.ocr.raw, "amount"),
strings.icontains(.scan.ocr.raw, "crypto"),
strings.icontains(.scan.ocr.raw, "wallet address"),
regex.icontains(.scan.ocr.raw, '\$\d{3}\.\d{2}\b'),
regex.icontains(.scan.ocr.raw,
'(\+\d|1.(\()?\d{3}(\))?\D\d{3}\D\d{4})'
),
regex.icontains(.scan.ocr.raw,
'\+?(\d{1,2})?\s?\(?\d{3}\)?[\s\.\-⋅]{0,5}\d{3}[\s\.\-⋅]{0,5}\d{4}'
)
)
// 1 of the following strings is found, representing common Callback brands
and (
1 of (
strings.icontains(.scan.ocr.raw, "geek squad"),
strings.icontains(.scan.ocr.raw, "lifelock"),
strings.icontains(.scan.ocr.raw, "best buy"),
strings.icontains(.scan.ocr.raw, "mcafee"),
strings.icontains(.scan.ocr.raw, "norton"),
strings.icontains(.scan.ocr.raw, "ebay"),
strings.icontains(.scan.ocr.raw, "paypal"),
)
// add additional logic for common language for paypal, which is a valid payment method
and not regex.icontains(.scan.ocr.raw,
"paypal[^\n]+accepted"
)
and not regex.icontains(.scan.ocr.raw,
"pay(ment)?.{0,30}(via|by) paypal"
)
and not regex.icontains(.scan.ocr.raw,
'\d{2,4} norton'
) // an address, example: 1234 Norton Road
and not regex.icontains(.scan.ocr.raw,
'sold on.{0,20}ebay'
) // "cannot be sold on Amazon and EBay", from a legit vendor
)
)
or any(ml.logo_detect(.).brands,
.name in ("PayPal", "Norton", "GeekSquad", "Ebay")
)
)
)
)
)
)
//
// This rule makes use of a beta feature and is subject to change without notice
// using the beta feature in custom rules is not suggested until it has been formally released
//
and (
not beta.profile.by_reply_to().any_messages_benign
or length(headers.reply_to) == 0
)
Detection logic
Scope: inbound message.
Callback phishing campaigns have been observed abusing Intuit Quickbooks services to send fraudulent invoices with callback phishing contents.
- inbound message
all of:
- sender.email.domain.root_domain in ('intuit.com', 'intuit.co.uk')
any of:
- headers.auth_summary.spf.pass
- headers.auth_summary.dmarc.pass
any of:
all of:
- length(attachments) is 0
- strings.replace_confusables(body.current_thread.text) matches 'mcafee|norton|geek.{0,5}squad|paypal|ebay|symantec|best buy|lifelock'
at least 3 of 14: body.current_thread.text matches any of 14 patterns
*purchase**payment**transaction**subscription**antivirus**order**support**help line**receipt**invoice**call**cancel**renew**refund*
any of
[body.current_thread.text, subject.subject]where:- . matches '\\b\\+?(\\d{1}.)?\\(?\\d{3}?\\)?.\\d{3}.?\\d{4}\\b'
any of:
- strings.replace_confusables(body.html.inner_text) matches '(?:Sold|Bill)[\\s\\xa0]To(?:\\:\\s+|\\n)[^\\n]+\\+?(\\d{1}.)?\\(?\\d{3}?\\)?.\\d{3}.?\\d{4}.*\\n'
- strings.replace_confusables(body.html.inner_text) matches '(?:Sold|Bill)[\\s\\xa0]To(?:\\:\\s+|\\n)[^\\n]+\\+\\d{1,3}[ilo0-9]{10}.*\\n'
- strings.replace_confusables(body.html.inner_text) matches '(?:Sold|Bill)[\\s\\xa0]To(?:\\:\\s+|\\n)[^\\n]+[ilo0-9]{3}\\.[ilo0-9]{3}\\.[ilo0-9]{4}.*\\n'
- strings.replace_confusables(body.html.inner_text) matches '(?:Sold|Bill)[\\s\\xa0]To(?:\\:\\s+|\\n)[^\\n]+[ilo0-9]{3}-[ilo0-9]{3}-[ilo0-9]{4}.*\\n'
- strings.replace_confusables(body.html.inner_text) matches '(?:Sold|Bill)[\\s\\xa0]To(?:\\:\\s+|\\n)[^\\n]+\\([ilo0-9]{3}\\)[\\s-]+[ilo0-9]{3}[\\s-]+[ilo0-9]{4}.*\\n'
- strings.replace_confusables(body.html.inner_text) matches '(?:Sold|Bill)[\\s\\xa0]To(?:\\:\\s+|\\n)[^\\n]+\\([ilo0-9]{3}\\)-[ilo0-9]{3}-[ilo0-9]{4}.*\\n'
- strings.replace_confusables(body.html.inner_text) matches '(?:Sold|Bill)[\\s\\xa0]To(?:\\:\\s+|\\n)[^\\n]+1\\s?[ilo0-9]{3} [ilo0-9]{3} [ilo0-9]{4}.*\\n'
all of:
- strings.replace_confusables(body.html.inner_text) matches '(?:Sold|Bill)[\\s\\xa0]To(?:\\:\\s+|\\n)[^\\n]+8\\d{9}.*\\n'
- strings.replace_confusables(body.html.inner_text) matches '\\+1'
all of:
- length(attachments) < 3
all of
attachmentswhere:- .file_extension is 'pdf'
any of
attachmentswhere all hold:- .file_extension is 'pdf'
any of
file.explode(.)where:- .scan.exiftool.page_count < 3
any of
file.explode(.)where:- length(.scan.ocr.raw) > 60
any of:
any of
file.explode(.)where all hold:at least 4 of:
- .scan.ocr.raw contains 'purchase'
- .scan.ocr.raw contains 'payment'
- .scan.ocr.raw contains 'transaction'
- .scan.ocr.raw contains 'subscription'
- .scan.ocr.raw contains 'antivirus'
- .scan.ocr.raw contains 'order'
- .scan.ocr.raw contains 'support'
- .scan.ocr.raw contains 'help line'
- .scan.ocr.raw contains 'receipt'
- .scan.ocr.raw contains 'invoice'
- .scan.ocr.raw contains 'call'
- .scan.ocr.raw contains 'helpdesk'
- .scan.ocr.raw contains 'cancel'
- .scan.ocr.raw contains 'renew'
- .scan.ocr.raw contains 'refund'
- .scan.ocr.raw contains 'amount'
- .scan.ocr.raw contains 'crypto'
- .scan.ocr.raw contains 'wallet address'
- .scan.ocr.raw matches '\\$\\d{3}\\.\\d{2}\\b'
- .scan.ocr.raw matches '(\\+\\d|1.(\\()?\\d{3}(\\))?\\D\\d{3}\\D\\d{4})'
- .scan.ocr.raw matches '\\+?(\\d{1,2})?\\s?\\(?\\d{3}\\)?[\\s\\.\\-⋅]{0,5}\\d{3}[\\s\\.\\-⋅]{0,5}\\d{4}'
all of:
at least 1 of 7: .scan.ocr.raw contains any of 7 patterns
geek squadlifelockbest buymcafeenortonebaypaypal
not:
- .scan.ocr.raw matches 'paypal[^\\n]+accepted'
not:
- .scan.ocr.raw matches 'pay(ment)?.{0,30}(via|by) paypal'
not:
- .scan.ocr.raw matches '\\d{2,4} norton'
not:
- .scan.ocr.raw matches 'sold on.{0,20}ebay'
any of
ml.logo_detect(.).brandswhere:- .name in ('PayPal', 'Norton', 'GeekSquad', 'Ebay')
any of:
not:
- beta.profile.by_reply_to().any_messages_benign
- length(headers.reply_to) is 0
Inspects: attachments[].file_extension, body.current_thread.text, body.html.inner_text, headers.auth_summary.dmarc.pass, headers.auth_summary.spf.pass, headers.reply_to, sender.email.domain.root_domain, subject.subject, type.inbound. Sensors: beta.profile.by_reply_to, file.explode, ml.logo_detect, regex.icontains, strings.icontains, strings.ilike, strings.replace_confusables.
Indicators matched (64)
| Field | Match | Value |
|---|---|---|
sender.email.domain.root_domain | member | intuit.com |
sender.email.domain.root_domain | member | intuit.co.uk |
regex.icontains | regex | mcafee|norton|geek.{0,5}squad|paypal|ebay|symantec|best buy|lifelock |
strings.ilike | substring | *purchase* |
strings.ilike | substring | *payment* |
strings.ilike | substring | *transaction* |
strings.ilike | substring | *subscription* |
strings.ilike | substring | *antivirus* |
strings.ilike | substring | *order* |
strings.ilike | substring | *support* |
strings.ilike | substring | *help line* |
strings.ilike | substring | *receipt* |
52 more
strings.ilike | substring | *invoice* |
strings.ilike | substring | *call* |
strings.ilike | substring | *cancel* |
strings.ilike | substring | *renew* |
strings.ilike | substring | *refund* |
regex.icontains | regex | \b\+?(\d{1}.)?\(?\d{3}?\)?.\d{3}.?\d{4}\b |
regex.icontains | regex | (?:Sold|Bill)[\s\xa0]To(?:\:\s+|\n)[^\n]+\+?(\d{1}.)?\(?\d{3}?\)?.\d{3}.?\d{4}.*\n |
regex.icontains | regex | (?:Sold|Bill)[\s\xa0]To(?:\:\s+|\n)[^\n]+\+\d{1,3}[ilo0-9]{10}.*\n |
regex.icontains | regex | (?:Sold|Bill)[\s\xa0]To(?:\:\s+|\n)[^\n]+[ilo0-9]{3}\.[ilo0-9]{3}\.[ilo0-9]{4}.*\n |
regex.icontains | regex | (?:Sold|Bill)[\s\xa0]To(?:\:\s+|\n)[^\n]+[ilo0-9]{3}-[ilo0-9]{3}-[ilo0-9]{4}.*\n |
regex.icontains | regex | (?:Sold|Bill)[\s\xa0]To(?:\:\s+|\n)[^\n]+\([ilo0-9]{3}\)[\s-]+[ilo0-9]{3}[\s-]+[ilo0-9]{4}.*\n |
regex.icontains | regex | (?:Sold|Bill)[\s\xa0]To(?:\:\s+|\n)[^\n]+\([ilo0-9]{3}\)-[ilo0-9]{3}-[ilo0-9]{4}.*\n |
regex.icontains | regex | (?:Sold|Bill)[\s\xa0]To(?:\:\s+|\n)[^\n]+1\s?[ilo0-9]{3} [ilo0-9]{3} [ilo0-9]{4}.*\n |
regex.icontains | regex | (?:Sold|Bill)[\s\xa0]To(?:\:\s+|\n)[^\n]+8\d{9}.*\n |
regex.icontains | regex | \+1 |
attachments[].file_extension | equals | pdf |
strings.icontains | substring | purchase |
strings.icontains | substring | payment |
strings.icontains | substring | transaction |
strings.icontains | substring | subscription |
strings.icontains | substring | antivirus |
strings.icontains | substring | order |
strings.icontains | substring | support |
strings.icontains | substring | help line |
strings.icontains | substring | receipt |
strings.icontains | substring | invoice |
strings.icontains | substring | call |
strings.icontains | substring | helpdesk |
strings.icontains | substring | cancel |
strings.icontains | substring | renew |
strings.icontains | substring | refund |
strings.icontains | substring | amount |
strings.icontains | substring | crypto |
strings.icontains | substring | wallet address |
regex.icontains | regex | \$\d{3}\.\d{2}\b |
regex.icontains | regex | (\+\d|1.(\()?\d{3}(\))?\D\d{3}\D\d{4}) |
regex.icontains | regex | \+?(\d{1,2})?\s?\(?\d{3}\)?[\s\.\-⋅]{0,5}\d{3}[\s\.\-⋅]{0,5}\d{4} |
strings.icontains | substring | geek squad |
strings.icontains | substring | lifelock |
strings.icontains | substring | best buy |
strings.icontains | substring | mcafee |
strings.icontains | substring | norton |
strings.icontains | substring | ebay |
strings.icontains | substring | paypal |
regex.icontains | regex | paypal[^\n]+accepted |
regex.icontains | regex | pay(ment)?.{0,30}(via|by) paypal |
regex.icontains | regex | \d{2,4} norton |
regex.icontains | regex | sold on.{0,20}ebay |
ml.logo_detect(attachments[]).brands[].name | member | PayPal |
ml.logo_detect(attachments[]).brands[].name | member | Norton |
ml.logo_detect(attachments[]).brands[].name | member | GeekSquad |
ml.logo_detect(attachments[]).brands[].name | member | Ebay |