Malicious PDF — malware analysis report

Static analysis result for SHA-256 83cd7a8067ce8d49…

MALICIOUS

PDF

75.9 KB Created: 2009-12-18 19:44:15 Authoring application: PDF Library 10.5.9 (via PDF Library 1.10.2)
MD5: a9d2c207d3308c22efb4095ba480e6d0 SHA-1: 760f313ba138db0b73dbea5df4478ebbdde6bcb9 SHA-256: 83cd7a8067ce8d494d69d20adc4c9f608569c0f3aa695052a78f6640fe9c5aa3
338 Risk Score

Malware Insights

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

The PDF file contains multiple critical heuristic firings indicating exploitation of CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992 through embedded JavaScript. A deobfuscated JavaScript file, 'legacy_pdfkit_stage_000.js', was extracted, suggesting it's the second-stage payload. The presence of ClamAV detections further confirms its malicious nature, likely acting as a downloader or exploit kit.

Heuristics 9

  • 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)
  • Collab.collectEmailInfo — CVE-2007-5659 critical CVE exact CVE_2007_5659
    PDF JavaScript calls Collab.collectEmailInfo — CVE-2007-5659 is a buffer overflow in Adobe Reader triggered by a long argument or heap-sprayed message field passed to Collab.collectEmailInfo(). Part of a series of Acrobat JS API exploits. (identified after JavaScript deobfuscation)
  • util.printf — CVE-2008-2992 critical CVE exact CVE_2008_2992
    PDF JavaScript calls util.printf() — CVE-2008-2992 is a stack buffer overflow in Adobe Reader triggered by a long format-specifier argument. Widely exploited in the wild after disclosure. (identified after JavaScript deobfuscation)
  • ClamAV: Pdf.Exploit.Agent-36110 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36110
  • 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.
  • ASCIIHexDecode filter (with exploit indicators) medium PDF_FILTER_HEX
    Hex-encoding filter present alongside exploit delivery indicators — often used to hide payload or shellcode bytes
  • 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.
  • 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_obj0007_000.js
f7c3fdf3bba75ad641155aff5b10ba3728aca8e9e684a6d41dbb1402cd1ec659
pdf-javascript-stream PDF /JS object 7 at offset 0x1A5 38358 bytes
legacy_pdfkit_stage_000.js
9ac76017773cb69bff87bd0b6aaa133ca12696ce27a0e0afdbce0649b62f4930
deobfuscated-js numeric array subtract-key decoded JavaScript at offset 0x1A5 10030 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).