Malicious PDF — malware analysis report

Static analysis result for SHA-256 efce0a92090064bc…

MALICIOUS

PDF

2.3 KB
MD5: 8e86ec64ca38a2c3bfc023f624d567d2 SHA-1: 43ef6398532971ee60db6763d80497878888ea0a SHA-256: efce0a92090064bc4028c7f6088d64e5a30c6979550bf8a5ba931ff76936b408
226 Risk Score

Malware Insights

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

The PDF file contains embedded and obfuscated JavaScript, including calls to `eval()` and `unescape()`, indicating an attempt to hide malicious code. Heuristics confirm the use of CVE-2009-4324, a known PDF vulnerability, and ClamAV detected a JavaScript exploit. The embedded JavaScript likely downloads and executes a second-stage payload, as suggested by the 'Js.Exploit.Shellcode-18' detection on an extracted artifact.

Heuristics 8

  • media.newPlayer — CVE-2009-4324 critical CVE exact CVE_2009_4324
    PDF JavaScript calls media.newPlayer — CVE-2009-4324 is a use-after-free in Adobe Reader's multimedia plugin triggered by media.newPlayer(). Actively exploited as a zero-day in December 2009. (identified after JavaScript deobfuscation)
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • 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_obj111611_000.js
e7d1232c16a6e584ebcad6ed89ed39659361935894de0b1df6aee2e4fe16ce04
pdf-javascript-stream PDF /JS object 111611 at offset 0x820 478 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
382aa66544450b561077773ab28f9a04e008ccf6e68ee054e756395fd7a8eabd
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x189 2427 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).