Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa01aa1f6b32a6e9…

MALICIOUS

PDF

118.4 KB
MD5: 269af854a4df19d2882fb12913cccd9f SHA-1: c197796eb6a1d24fc8ae531cde63eb108c811ea4 SHA-256: aa01aa1f6b32a6e9d389673d9faa2ef2b6af317278dcd474ccd007e35562e3b5
166 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript streams, with high-confidence heuristics indicating the use of eval() and a large comment-padded eval stager. ClamAV detected this file as 'Pdf.Exploit.Agent-36086', strongly suggesting it's an exploit delivery mechanism. The obfuscated JavaScript likely attempts to download and execute a secondary payload, a common technique for malware distribution.

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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0006_000.js
f3207652337b14cf5e198fa8e64f2bc6fe558d263d96c4cd732b284baa4b416a
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626701 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).
legacy_pdfkit_stage_000.js
5d8e02655fcb0bfe4451c34bcbccc2de9c545f657cc6d66cc5ee4e94af8494a5
deobfuscated-js double percent-decoded annotation JavaScript at offset 0x143 262116 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 590 long base64-like blob(s).