Malicious PDF — malware analysis report

Static analysis result for SHA-256 52017f45d5fcbe45…

MALICIOUS

PDF

92.3 KB
MD5: 7dccfa231c7c08fbe0f23be4505ce25c SHA-1: 94e1d286a0fd4c67762059e54b0db5100ce61e23 SHA-256: 52017f45d5fcbe45cb417c33b36e8253a36cb7a16e9344521eb86dee8e3d369b
378 Risk Score

Malware Insights

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

This PDF file contains multiple critical heuristic firings indicating exploitation of known PDF vulnerabilities (CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, CVE-2008-2992). These vulnerabilities are used to execute embedded JavaScript, as confirmed by the 'PDF_JAVASCRIPT' and 'PDF_JS' firings. The extracted JavaScript, specifically 'legacy_pdfkit_stage_000.js', is identified by ClamAV as 'Js.Exploit.Shellcode-18', suggesting it's a malicious payload. The overall behavior points to a PDF-based exploit kit designed to deliver a secondary malicious payload.

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
98c50466355d345c284400bfd17ea072de048b12610cb0c8af9aea8bae8950eb
pdf-javascript-stream PDF /JS object 8 at offset 0x1E7 3066 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36307
Obfuscation or payload: unlikely
legacy_pdfkit_stage_000.js
3f7be24941ce890aa6fdb794968083d9821562ea9dfbce042c556a86e7e6421c
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0xE15 6042 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