Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4a77c312d8ada1c…

MALICIOUS

PDF

2.2 KB
MD5: 472c41652ca22bfea429084362d46597 SHA-1: 711885829021a940a8e0427a30892597e4935c77 SHA-256: e4a77c312d8ada1c90207e20c2c1a5875e4c877b0f4c6b388687d94d1b9979f0
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 Command and Scripting Interpreter: PowerShell T1204.002 Malicious File: Malicious File

The PDF file contains embedded JavaScript, which is heavily obfuscated using `eval()` and `unescape()` functions. This script is designed to execute malicious code, as indicated by the ClamAV detection signature 'Pdf.Exploit.Agent-36082'. The primary function of the script appears to be downloading and executing a secondary payload, a common technique for initial access and further system compromise. The heuristic firings strongly suggest an exploit attempting to run arbitrary code.

Heuristics 7

  • ClamAV: Pdf.Exploit.Agent-36082 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36082
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj111611_000.js
772da696bdb365f3f1eb4ea6af881baad391be62f3591b19f2f9827fcc4c9b53
pdf-javascript-stream PDF /JS object 111611 at offset 0x7E6 479 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
0d0a32a9bacdc0ffd025772ec216a41ec54eaf91ada9d707e10c0f8ab7b0014b
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x189 2834 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).