Malicious PDF — malware analysis report

Static analysis result for SHA-256 21ef3ff9797b4374…

MALICIOUS

PDF

76.0 KB Created: 2009-12-31 19:49:72 Authoring application: PDF Library 8.8.6 (via PDF Library 5.4.1)
MD5: 0548f4ce0464f38ac83f7fbcf864a767 SHA-1: 73c09c8c51cbe223c6c2bb4ab07043a1f9c5b0be SHA-256: 21ef3ff9797b4374a3255dc6e966a8acb272da0cb36f5b1d8973c502a714fdbd
340 Risk Score

Malware Insights

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

The PDF file contains multiple critical heuristic firings indicating exploitation of CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992 through embedded JavaScript. An extracted JavaScript file, 'legacy_pdfkit_stage_000.js', was also flagged as suspicious. This suggests the document's primary purpose is to exploit these vulnerabilities to download and execute a secondary payload, as indicated by the ClamAV detection on the extracted artifact.

Heuristics 10

  • 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.
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PSSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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
34f5f6b17c64aaba9e901e73111b3c0d38872df14f82cf96ef520b6ff67647c0
pdf-javascript-stream PDF /JS object 7 at offset 0x1A5 38416 bytes
legacy_pdfkit_stage_000.js
9d2fa16074aec6cd3bd36ac31c848feac89b3e08f45855fbd850bfd04cd71dba
deobfuscated-js numeric array subtract-key decoded JavaScript at offset 0x1A5 9958 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).