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High Severity

Attachment: HTML smuggling with excessive line break obfuscation

Labels

Credential Phishing
Malware/Ransomware
Encryption
Evasion
HTML smuggling
Scripting
Archive analysis
Content analysis
File analysis
HTML analysis
Javascript analysis

Description

Credential Phishing attacks have been observed using excessive line breaks to obfuscate javascript functions within html files.

References

No references.

Sublime Security
Created Sep 8th, 2023 • Last updated Sep 8th, 2023
Feed Source
Sublime Core Feed
Source
GitHub
type.inbound
and any(attachments,
        (
          .file_extension in~ ("html", "htm", "shtml", "dhtml")
          or .file_extension in~ $file_extensions_common_archives
          or .file_type == "html"
        )
        and any(file.explode(.),
                any(.scan.strings.strings,
                // return new line padded obfuscation 
                    regex.contains(., '(\\r\\n\S{2}){50,}')
                    and strings.contains(., 'decodeURIComponent')
                )
        )
)
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