Malicious PDF — malware analysis report

Static analysis result for SHA-256 e5735915d90421c3…

MALICIOUS

PDF

132.5 KB
MD5: f98ab96b9533a5fd61f0a9d5fbbeb987 SHA-1: 462354a6d2f433972d25c18b1d69602a02ad3c43 SHA-256: e5735915d90421c35de85dca94c174f60348f48fc49df4b4303f9014d64c7247
258 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that leverages multiple known vulnerabilities (CVE-2009-0927, CVE-2007-5659, CVE-2008-2992) through the use of `Collab.getIcon`, `Collab.collectEmailInfo`, and `util.printf` functions. The heuristic firings indicate that this JavaScript is obfuscated and likely attempts to download and execute a secondary payload, as suggested by the ClamAV detection 'Js.Exploit.Shellcode-18' on an extracted artifact. The extracted JavaScript files, `javascript_obj0008_000.js` and `legacy_pdfkit_stage_000.js`, are the primary indicators of this malicious activity.

Heuristics 7

  • 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.
  • 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
b20130c26811506e41793877d13b8b05ef4027a9a30fa449b4d9940a5a0b5961
pdf-javascript-stream PDF /JS object 8 at offset 0x1E7 2095 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_000.js
66db9f006539cf164d3b25c6a072697ee0eed92fb7e7f69c92919d1294673526
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0xA4A 14745 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s).