Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8ee3e1a4d5d4a06…

MALICIOUS

PDF

15.7 KB
MD5: 0fec73fbc23b23ea0f2d150c40ed97db SHA-1: 22f381e8346bf0c600c7d373398b11a33f4ee468 SHA-256: f8ee3e1a4d5d4a06584ebb5d6e5cac3eec509be8e47c0ea5405efb09c26d634f
166 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, including a large comment-padded eval stager. This indicates an attempt to obfuscate malicious code execution. The presence of PDF_JAVASCRIPT, PDF_JS, PDF_EVAL, and PDF_FROMCHARCODE heuristics, along with the ClamAV detection of 'Pdf.Exploit.Agent-36086', strongly suggests the document is designed to exploit a PDF vulnerability. The primary function appears to be downloading and executing a second-stage payload, as indicated by the eval stager.

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
d605b34aa3b14b09945059d7f1316e8e4ac42b3df056a74431dd3f5cccb6eccb
pdf-javascript-stream PDF /JS object 6 at offset 0x143 424819 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).