High Severity
Attachment: HTML smuggling 'body onload' linking to suspicious destination
Description
Potential HTML Smuggling. This rule inspects HTML attachments that contain a single link and leveraging an HTML body onload event. The linked domain must be in the URLhaus trusted repoters list, or have a suspicious TLD.
References
No references.
Sublime Security
Created Sep 21st, 2023 • Last updated Sep 22nd, 2023
Feed Source
Sublime Core Feed
Source
type.inbound
and any(attachments,
(
.file_extension in~ ("html", "htm", "shtml", "dhtml", "xhtml")
or (
.file_extension is null
and .file_type == "unknown"
and .content_type == "application/octet-stream"
)
or .file_extension in~ $file_extensions_common_archives
or .file_type == "html"
or .content_type == "text/html"
)
and any(file.explode(.),
not length(.scan.url.invalid_urls) > 0
and length(.scan.url.urls) == 1
and any(.scan.strings.strings, strings.ilike(., "*body onload*"))
and (
any(.scan.url.urls,
.domain.root_domain in $abuse_ch_urlhaus_domains_trusted_reporters
// To-do uncomment below when list is created
//or .domain.root_domain in $suspicious_root_domains
or .domain.tld in $suspicious_tlds
)
)
)
)
Playground
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