Malicious PDF — malware analysis report

Static analysis result for SHA-256 3d453d2bd5a76b44…

MALICIOUS

PDF

118.4 KB
MD5: 336b11340760b13ab55e381002916801 SHA-1: 39e799cad5e065fb403a4ce418434d8271d3c929 SHA-256: 3d453d2bd5a76b448c828dbeaf88a75c63d3e3d9545a45ef43ed0468f1ceccf7
166 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript, with high-confidence heuristics indicating the use of eval() and a large comment-padded eval stager. ClamAV also identified this as Pdf.Exploit.Agent-36086. The embedded JavaScript is heavily obfuscated, but the presence of eval() and String.fromCharCode suggests it is designed to decode and execute arbitrary code, likely to download and run a second-stage payload. The document body was not sufficiently readable to determine a specific lure.

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
f933c3de5bc2564d60f403a1eeb4d1a86fc48f1067a2d2c8771f7580471f7049
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626077 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).