Malicious PDF — malware analysis report

Static analysis result for SHA-256 f76dc21adfc86dc4…

MALICIOUS

PDF

132.6 KB
MD5: 74b17e79d6dc768c97a0d250150a2d43 SHA-1: 09dcafb6fb08f00f06227dbed1796b2657f33e49 SHA-256: f76dc21adfc86dc46b88b20ce63ec1302e5e3e9ee0556db5935fc20d3ad64853
258 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/Shell Scripting: JavaScript T1204.002 Malicious File: User Execution: Malicious JavaScript

The PDF file contains multiple critical heuristic firings indicating exploitation of CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992 through embedded JavaScript. The embedded JavaScript streams, particularly the deobfuscated legacy_pdfkit_stage_000.js, are flagged by ClamAV as Js.Exploit.Shellcode-18. This strongly suggests the script is designed to download and execute a secondary malicious payload. The attack pattern is consistent with a drive-by compromise leveraging known PDF reader vulnerabilities.

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
5b17a71831e251082cc124ef59fcc3b6ede754925c3652f8836a81c50037ea08
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
8cd1e4c3b415b3eb6fc9b1075536533308fa86854d28cb7ad645a0a4e6bd6e97
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0xA4A 14757 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s).