Malicious PDF — malware analysis report

Static analysis result for SHA-256 fcd4be9e34539966…

MALICIOUS

PDF

118.8 KB
MD5: 09379a477820a51d6afb0b3a86b9cc4f SHA-1: f41ef0cd9947a2258cf7bb96ccd4132cb8e3a917 SHA-256: fcd4be9e345399661426b0f21c5de2c7ddd9db8380c7ccdaa743fb0c7e6c89db
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious JavaScript

The file is a PDF containing embedded JavaScript, as indicated by multiple PDF_JAVASCRIPT and PDF_JS heuristics. The presence of PDF_EVAL and PDF_JS_LARGE_COMMENT_PADDED_EVAL strongly suggests that the JavaScript is designed to execute arbitrary code. ClamAV detection as 'Pdf.Exploit.Agent-36086' further confirms its malicious nature. The JavaScript likely acts as a stager to download and execute a second-stage payload.

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
61046299e706d3cb4b1183f12c9309c76b549c1b8b80e14180d86a8b35ecb1ad
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627485 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).