High Severity
Fake request for tax preparation
Description
Unknown sender requesting assistance with tax preparation. This is associated with known threat actor activity, TA576.
References
No references.
Sublime Security
Created Mar 27th, 2024 • Last updated Jul 16th, 2025
Feed Source
Sublime Core Feed
Source
type.inbound
and length(body.current_thread.text) < 1250
and any(beta.ml_topic(body.current_thread.text).topics,
.name == "Financial Communications"
)
// there are no links, all the links are to aka.ms, or an extraction from a warning banner that match the senders domain
and (
length(body.links) == 0
or length(filter(body.links,
(
.display_text is null
and .display_url.url == sender.email.domain.root_domain
)
or .href_url.domain.domain == "aka.ms"
or network.whois(.display_url.domain).days_old < 30
)
) == length(body.links)
)
and length(attachments) == 0
and (strings.ilike(subject.subject, "*tax*") or length(subject.subject) < 15)
and strings.icontains(body.current_thread.text, "tax")
and (
strings.like(body.current_thread.text,
"*return*",
"*record*",
"*CPA*",
"*filing*",
"*extension*"
)
or strings.ilike(body.current_thread.text,
"*tax preparer*",
"*tax*processing*"
)
)
and (
strings.ilike(body.current_thread.text,
"*necessary documents*",
"*required documents*",
"*paperwork*",
"*in search of*",
"*tax service*",
"*professional help*",
"*prepare*tax return*",
"*service*tax return*",
"*seeking*tax preparer*",
"*assist*processing*tax*",
"*schedule*call*",
"*zoom meeting*",
"*discuss*fees*",
"*W2*",
"*CPA*"
)
// suspicious patterns
or (
strings.icontains(body.current_thread.text, sender.display_name)
and 2 of (
(
length(headers.reply_to) > 0
and all(headers.reply_to,
.email.domain.root_domain != sender.email.domain.root_domain
)
),
(
headers.return_path.email is not null
and headers.return_path.email != sender.email.email
),
headers.return_path.domain.root_domain in ("amazonses.com")
)
)
)
and (
(
profile.by_sender().prevalence in ("new", "outlier")
and not profile.by_sender().solicited
)
or (
profile.by_sender().any_messages_malicious_or_spam
and not profile.by_sender().any_messages_benign
)
)
and not profile.by_sender().any_messages_benign
Playground
Test against your own EMLs or sample data.