Malicious PDF — malware analysis report

Static analysis result for SHA-256 399b41e77c8849f3…

MALICIOUS

PDF

1.9 KB
MD5: f625f5b40652be776b8588fc462904ab SHA-1: bce639339b35bfae93dc26edadbe6516b23a7379 SHA-256: 399b41e77c8849f36ff818b2b95b230dc96e77712177fdd5c34ab46c89455bc0
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link T1071.001 Web Protocols T1204 User Execution

The PDF sample contains embedded JavaScript that utilizes `eval()` and `unescape()` functions, indicating obfuscation. The critical CVE-2009-0927 heuristic firing confirms the exploitation of a known vulnerability in PDF viewers via the `Collab.getIcon` method. The embedded JavaScript is likely designed to download and execute a second-stage payload from a remote source, a common technique for initial access.

Heuristics 7

  • Collab.getIcon — CVE-2009-0927 critical CVE exact CVE_2009_0927
    PDF JavaScript calls Collab.getIcon — CVE-2009-0927 is a stack buffer overflow in Adobe Reader triggered by Collab.getIcon() with a crafted argument. Allows arbitrary code execution. (identified after JavaScript deobfuscation)
  • 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
433d6141b5fc932a52d94051061c1f7566cbde37bb51ce636d76e20ed4ab2bf6
pdf-javascript-stream PDF /JS object 111611 at offset 0x6CF 297 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
712822addbda09bddb2f7a516a37dd775d6b5d745fc9d5d2dc7a24c508a0ad4b
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x189 2637 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).