Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c9ea35ef6dfa1fc…

MALICIOUS

PDF

15.7 KB
MD5: 2fdb06d19655cc4e54790f56a23bc9b5 SHA-1: b85ff43ec79f40c9960eac9483b6988e09cd5701 SHA-256: 8c9ea35ef6dfa1fc02b3576e717b6b912076b901814a9eaf22cfd5989375e1f3
166 Risk Score

Malware Insights

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

The PDF document contains embedded JavaScript, identified by multiple heuristics including 'PDF_JAVASCRIPT', 'PDF_JS', and 'PDF_EVAL'. A 'PDF_JS_LARGE_COMMENT_PADDED_EVAL' heuristic specifically indicates a stager designed to obfuscate the execution of JavaScript. The ClamAV detection 'Pdf.Exploit.Agent-36086' further confirms the malicious nature of this PDF. The primary attack vector appears to be the execution of this embedded JavaScript, which is likely responsible for downloading and executing a secondary 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
308c2f1947b4a27a265344e8a3b7d0b9cb29b0f7b125d1630141e5f91b956842
pdf-javascript-stream PDF /JS object 6 at offset 0x143 425383 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).