Malicious PDF — malware analysis report

Static analysis result for SHA-256 76767d149c8a2cb3…

MALICIOUS

PDF

13.6 KB
MD5: 7efc0b677709f7e8b094eed5cfc6f92e SHA-1: 26a24151f83cefbe2f6b3808a268f5663d233bce SHA-256: 76767d149c8a2cb371b825b9d831981d1e6f3a0c5df7621f44fdd2b21d069a17
298 Risk Score

Malware Insights

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

The PDF file contains obfuscated JavaScript that exploits multiple Adobe Reader vulnerabilities including CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. The script utilizes a custom Base64 decoder to unwrap encoded layers and execute a second-stage payload, as indicated by the ClamAV detection 'Js.Exploit.Shellcode-18'. The primary intent is to leverage these exploits for arbitrary code execution.

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 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.
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits
  • 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
c05bc2a52c199932168ce81d668fd98e8a36079b3878255bbbc4f546e835cd4d
pdf-javascript-stream PDF /JS object 8 at offset 0x1E7 13205 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
custom_b64_stage_000.js
85595cebec5d330d2e7b4f562727e916c3da84c2875a0cdaad69424851f49b83
deobfuscated-js custom Base64 decoded JavaScript layer 2 (PDF /JS object 8) at offset 0x6E8 6500 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s).