Malicious PDF — malware analysis report

Static analysis result for SHA-256 a08b970f70faaf7d…

MALICIOUS

PDF

118.7 KB
MD5: 969875f8829fadbd8bf97d6a4be53dfd SHA-1: 4e36867b058837fa1f6b38841b272786cd25c34f SHA-256: a08b970f70faaf7d1ec3244d2885587969fc6a6d6932f4d2fc1c612330a3b161
166 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_EVAL. A critical ClamAV detection of 'Pdf.Exploit.Agent-36086' strongly suggests a known exploit. The presence of a large comment-padded JavaScript eval stager further points to a sophisticated obfuscation technique commonly used to hide malicious code. The primary function appears to be the execution of this JavaScript, which is likely designed to download and execute a secondary payload, a common tactic for initial compromise.

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
26fe60f1b52716cf06e2dae13d6dfc88a951f3dc8391f126fe7bc5710b1d748a
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627333 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).