Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ab5a047d12a7fae…

MALICIOUS

PDF

21.1 KB Created: 2012-09-17 23:33:20 +04:00 Authoring application: Adobe Acrobat 10.0 (via Acrobat Web Capture 10.0)
MD5: 777bab9678b217f0422e2d1f34b5e518 SHA-1: 4ff46be676208fbfdf803c375578af277f732bf0 SHA-256: 4ab5a047d12a7fae5e6eaab95983a7a1ea705e1b4e094c84759b93a064fa9f2a
416 Risk Score

Malware Insights

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

The PDF file contains multiple critical heuristic firings indicating the exploitation of several CVEs related to PDF JavaScript execution. The embedded JavaScript is heavily obfuscated using a base-31 pair stager, and further processed with String.fromCharCode. The ClamAV detection name 'Pdf.Exploit.CoolExploitKit-6308636-0' suggests this is part of a known exploit kit. The primary function of the script appears to be downloading and executing a second-stage payload.

Heuristics 11

  • 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.CoolExploitKit-6308636-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.CoolExploitKit-6308636-0
  • Base-N pair JavaScript stager high PDF_BASE_N_PAIR_JS_STAGER
    PDF JavaScript stores a long payload as character pairs decoded with parseInt(radix) and String.fromCharCode, then evals the result. The decoder only handles bounded pair tables and only fires when the recovered stage contains exploit-like JavaScript.
  • Suspicious extracted artifact high 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.
  • String.fromCharCode medium PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically
  • 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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/xap/1.0/
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/pdf/1.3/

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0019_000.js
c1a037b227bd7acff8c879bedf4715aabe57a224701e771b8625490353d3bf4a
pdf-javascript-stream PDF /JS object 19 at offset 0x487 9318 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 5 long base64-like blob(s).
base_n_pair_stage_000.js
105cf8e81605f02d6fbd4148da7e24be389b34b5e00ac38b3002d26de1b59cbf
deobfuscated-js base-31 pair decoded JavaScript at offset 0x495 4143 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
icc_00_off00002fac.icc
653b586c4707574ffcd648ba35494daed2c76ceafcf4c07d315ed961b1dc347f
pdf-icc-profile PDF ICC profile at offset 0x2FAC 408 bytes
icc_01_off00003247.icc
2b3aa1645779a9e634744faf9b01e9102b0c9b88fd6deced7934df86b949af7e
pdf-icc-profile PDF ICC profile at offset 0x3247 3144 bytes