Malicious PDF — malware analysis report

Static analysis result for SHA-256 249404936cc5bfe2…

MALICIOUS

PDF

118.7 KB
MD5: 8cd02401ebd3e17f244a612c150f3dbe SHA-1: d9f9ba661566109e1f060ad851cf201264ed3e69 SHA-256: 249404936cc5bfe20cf9b0f204b0e1f40494a4a265950295e1ea7d1b5ecd0424
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1059.007 JavaScript

The PDF file contains embedded JavaScript, including a large comment-padded eval stager and multiple calls to eval() and String.fromCharCode(). These heuristics, along with the ClamAV detection of 'Pdf.Exploit.Agent-36086', strongly indicate that the script is designed to de-obfuscate and execute malicious code. The primary purpose appears to be downloading and executing a second-stage payload, though the exact nature of the payload cannot be determined from the provided evidence.

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
a6b81fadbb616266a2bd585a08b33346be02f02d3eac5f258eea9fe43ebc6cd8
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627565 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).