Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8cc27171b0d6909…

MALICIOUS

PDF

118.6 KB
MD5: 4d4c1168df812b7bcaeb9b2b904cfe4b SHA-1: 0f4c5b1f452249fbce42ac87fd030aeadbd5a6c8 SHA-256: a8cc27171b0d690948d3f411c0d247f1f9e9950f1a508b32b5096230b40b1eb4
166 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_EVAL. A high-confidence heuristic, PDF_JS_LARGE_COMMENT_PADDED_EVAL, suggests a stager pattern commonly used to obfuscate malicious JavaScript. The ClamAV detection of 'Pdf.Exploit.Agent-36086' further confirms its malicious nature. The embedded JavaScript, named 'javascript_obj0006_000.js', is likely responsible for downloading and executing a secondary payload, which is a common attack vector for PDF-based malware.

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
3b23a7eca3bbb2196118f70af41e991bd0e637c4786aba08829ba5e68efb09ac
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627670 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).