Malicious PDF — malware analysis report

Static analysis result for SHA-256 85961fe4bb2f7a1a…

MALICIOUS

PDF

2.3 KB
MD5: 23a7aaedb5c0b023ac8f7e7aaafed6df SHA-1: 611b64884d537be2c3e4aae02c0e50f54d75199a SHA-256: 85961fe4bb2f7a1a3157be6ee6009969cb4d95fb8ab6046c8d7d2ad5a173265e
228 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link

The PDF file contains embedded JavaScript that utilizes eval() and unescape() functions, indicating obfuscation. The critical CVE-2009-0927 heuristic confirms the exploitation of a known vulnerability (Collab.getIcon) within the PDF structure. This exploit is designed to execute the embedded JavaScript, which is likely responsible for downloading and executing a secondary malicious payload. The presence of ClamAV detection further supports the malicious nature of the file.

Heuristics 8

  • 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)
  • ClamAV: Pdf.Exploit.Agent-36082 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36082
  • 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
772da696bdb365f3f1eb4ea6af881baad391be62f3591b19f2f9827fcc4c9b53
pdf-javascript-stream PDF /JS object 111611 at offset 0x841 479 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
431f65ed38444d50d43927f563ff02a89ad3a756634a3b3bc88fcf72fe0fbe6f
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x189 2625 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).