Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6cfb722a9b59853…

MALICIOUS

PDF

174.6 KB
MD5: af1cde53c8c9c0bcab5ea7d027c3ac1c SHA-1: 633bc2d35a5c9bb1e2ce85a058094c1e1318d0e7 SHA-256: b6cfb722a9b59853c2e828d30776621a89584a9e6791ecabcab9e23cdd3d5a06
318 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that exploits multiple known vulnerabilities (CVE-2009-0927, CVE-2007-5659, CVE-2008-2992) through the use of Collab.getIcon, Collab.collectEmailInfo, and util.printf. The deobfuscated JavaScript, legacy_pdfkit_stage_000.js, likely serves as a downloader for a second-stage payload. ClamAV detections further confirm the malicious nature of the file and its extracted artifacts.

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)
  • 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-35932 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35932
  • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0008_000.js
0229ec0b44ac0d4ef4c6f840226eec61a8665b590699699e7af46cf6d76c76db
pdf-javascript-stream PDF /JS object 8 at offset 0x1E7 3903 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36307
Obfuscation or payload: unlikely
legacy_pdfkit_stage_000.js
9b1f3847d37161138db95092b7b6510f49b813d34ef28563c6aeeca3f5969107
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x115A 8288 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s).