Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc51e7aa995a63b6…

MALICIOUS

PDF

2.2 KB
MD5: 17eac7e2600c20f8d7a4b6f7287ad7df SHA-1: 9861696c4b722546e26b314603b89f55a2d6a980 SHA-256: bc51e7aa995a63b6359f50db599caa84afc40bb257ea066ef4d1f3e2d92c6308
196 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Exploit.Agent-36098, indicating it contains known exploit code. High-severity heuristics like PDF_EVAL and PDF_UNESCAPE, along with ML classification, confirm its malicious nature. The embedded JavaScript, particularly the use of eval() and unescape(), suggests it's designed to deobfuscate and execute a payload, likely leading to arbitrary code execution.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 7

  • ClamAV: Pdf.Exploit.Agent-36098 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36098
  • 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
e1ab3bbf30605cecdce6db9d2556198626dbb178f7a4cb471a9436bb6e8bd92f
pdf-javascript-stream PDF /JS object 111611 at offset 0x78A 462 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
86c04dd3e2fe1ef84e089ed35aae5bca8fcb512d08cf8f823973ed1a29436ee5
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x189 2810 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).