Malicious PDF — malware analysis report

Static analysis result for SHA-256 f23ecc3d252274ae…

MALICIOUS

PDF

118.7 KB
MD5: 326f6d170746c70965e63529b765513d SHA-1: 55fe66b653920a71d6113b80cd7253008dff147c SHA-256: f23ecc3d252274aea444c863676b3d737c52382a2ff63bf082b8cc2d75058dd6
166 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, including a large, comment-padded eval stager. This indicates the file is designed to execute malicious code. The presence of 'eval()' and 'String.fromCharCode' functions within the JavaScript stream strongly suggests code obfuscation and dynamic execution, typical of downloaders or exploit stagers. The ClamAV detection 'Pdf.Exploit.Agent-36086' further confirms its malicious nature. The primary attack pattern involves exploiting PDF vulnerabilities to run this script, which likely leads to the download and execution of further malicious content.

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
fb5413375ffaa9e5ee125ed9ab18904a8f453f520841ac498e425af237ece82f
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627294 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).