Malicious PDF — malware analysis report

Static analysis result for SHA-256 af5a5505bf771e8c…

MALICIOUS

PDF

298.8 KB
MD5: 7f7be56d713d63ebedb4303c487912c9 SHA-1: 08ace3505af18d3fbb204e511ee2b57cfe06d9e4 SHA-256: af5a5505bf771e8c49ea71b44366e4426a18b70b75cec4cc05fc40ecc1656869
378 Risk Score

Malware Insights

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

The sample is a PDF file that exploits several known vulnerabilities including CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. These exploits are used to execute embedded JavaScript. The extracted JavaScript, particularly 'legacy_pdfkit_stage_000.js', is heavily obfuscated but appears to be designed to download and execute a second-stage payload. ClamAV detections further confirm the malicious nature of the file and its extracted artifacts.

Heuristics 9

  • 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)
  • 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-36307 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36307
  • 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.
  • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0008_000.js
b0a52c2ee7a11c3b3823e2a6e9136ed8d8447d5391facdfe864e5fcf0433216f
pdf-javascript-stream PDF /JS object 8 at offset 0x1E7 3462 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36307
Obfuscation or payload: unlikely
legacy_pdfkit_stage_000.js
dfb1ba8bf60db1e9763baf796f312d5d1c9632ba5649c4d32f1926658b9eb387
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0xFA1 20111 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
42025b552c7960b53abcd8cd732b01c8d109eccfdfefc352b9826c4d5807d414
deobfuscated-js cross-stage annotation API aliases at offset 0x1E7 81 bytes