Malicious PDF — malware analysis report

Static analysis result for SHA-256 49c03455daa35cd7…

MALICIOUS

PDF

118.6 KB
MD5: 69297242c4856b15114728cda320072b SHA-1: 5c9b273eebcefa05578d9fdcba0068788abcf696 SHA-256: 49c03455daa35cd764fc34f21d40d355b6152fc6e8a6e0c77b65d702fd8b2baa
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1566.001 Spearphishing Attachment T1071.001 Web Protocols

The PDF contains embedded JavaScript with multiple high-severity heuristic firings, including `PDF_EVAL` and `PDF_JS_LARGE_COMMENT_PADDED_EVAL`. This indicates the script is designed to obfuscate its actions and likely download and execute a second-stage payload. The ClamAV detection `Pdf.Exploit.Agent-36086` further confirms its malicious nature. The document body was unreadable, so the rationale is based on the script's behavior and the ClamAV signature.

Heuristics 7

  • ClamAV: Pdf.Exploit.Agent-36086 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36086
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • Large comment-padded JavaScript eval stager high PDF_JS_LARGE_COMMENT_PADDED_EVAL
    PDF JavaScript contains a very large stream padded with long random-looking block comments around String.fromCharCode and eval. This is an exploit-kit obfuscation shape used to bury a decoder and recovered stage inside noise, not normal PDF form automation.
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0006_000.js
6001f5d97410430854616b44fbb74c8b86c9bac0e76061848edcf6a44595539a
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626408 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 42 long base64-like blob(s).