Malicious PDF — malware analysis report

Static analysis result for SHA-256 f29af092191889fb…

MALICIOUS

PDF

118.6 KB
MD5: 561a2892e73cd23ade8433fc1b2a2e89 SHA-1: edcebdafffc3d7df713d8b4be575df268e9869fa SHA-256: f29af092191889fb19e9fb5170872848c9c445eca0727e5d95d528696104fdf8
166 Risk Score

Malware Insights

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

The PDF file contains multiple heuristic firings indicating embedded and obfuscated JavaScript, including the use of eval() and String.fromCharCode. ClamAV detection as 'Pdf.Exploit.Agent-36086' strongly suggests a malicious exploit. The presence of a large JavaScript stream further supports the conclusion that the PDF is designed to execute malicious code, likely for downloading and executing a second-stage 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
0b18ff6108350200feb0791dea1e3550df9061d52a5b485e61dd0472b2aa9cf1
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627189 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).