Malicious PDF — malware analysis report

Static analysis result for SHA-256 aab82715b0f1a206…

MALICIOUS

PDF

15.7 KB
MD5: 04c451107d496db9c3d2c061e7ceb0cd SHA-1: 565d397c535173625b83232bb4bfae95d8eed278 SHA-256: aab82715b0f1a206e6ae6c38a34359c3c51dd3af7d9696716b5e5a781e709e4e
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.002 Malicious File

The PDF file contains embedded JavaScript that utilizes eval() and String.fromCharCode, indicating an attempt to obfuscate malicious code. The heuristic 'PDF_JS_LARGE_COMMENT_PADDED_EVAL' strongly suggests a stager designed to download and execute further content. 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-based PDF.

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
5c3ba54fd3fcf5646f634899fa071d1a9300c99bd489d4423bc6c299617a55fc
pdf-javascript-stream PDF /JS object 6 at offset 0x143 425771 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).