Malicious PDF — malware analysis report

Static analysis result for SHA-256 a90af706c6cc5821…

MALICIOUS

PDF

118.5 KB
MD5: 0cf41f45516721b654f0e7daff7912ce SHA-1: 7a77252d771a627bcda740224a8a4549f455c701 SHA-256: a90af706c6cc5821a7b28dc9b2f65a834a9ef08b36c12b123b035705447fb6ca
166 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, as indicated by multiple heuristic firings including 'PDF_JAVASCRIPT', 'PDF_JS', and 'PDF_EVAL'. The 'PDF_JS_LARGE_COMMENT_PADDED_EVAL' heuristic suggests a stager pattern. The ClamAV detection 'Pdf.Exploit.Agent-36086' further confirms malicious intent. The embedded JavaScript file 'javascript_obj0006_000.js' is the primary artifact, likely responsible for executing the exploit.

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
970aed42117343e23b67aa52ebd4ada5d64b29d8785061f483a41433c2968433
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626649 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).