Malicious PDF — malware analysis report

Static analysis result for SHA-256 7faea4c4a0a6c65b…

MALICIOUS

PDF

118.5 KB
MD5: 2e4cf36a8237f0d7dd76e5b0cb0ef7b9 SHA-1: 95f80142968997dcdb327acd7f1fbde77b383073 SHA-256: 7faea4c4a0a6c65b7fcb7aeb192057bb72f9893567fe9fa8c9b8018b96354cb4
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 that utilizes eval() and String.fromCharCode, indicating an attempt to obfuscate malicious code. The 'Large comment-padded JavaScript eval stager' heuristic strongly suggests the script is designed to download and execute a secondary payload. ClamAV detection as 'Pdf.Exploit.Agent-36086' further confirms its malicious nature. The lack of readable document body text prevents a more specific determination of the lure, but the technical indicators point to a typical exploit delivery mechanism.

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
5853e2944e0f1cfd5a337a3267280f7fc8480a01fbe6695b22ec72cdf9a71232
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626420 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).