Malicious PDF — malware analysis report

Static analysis result for SHA-256 f846eaec28330ca0…

MALICIOUS

PDF

27.1 KB Created: 2012-09-17 23:33:20 +04:00 Authoring application: Adobe Acrobat 10.0 (via Acrobat Web Capture 10.0)
MD5: c48f83135f6f0f72ab814c1c5b67e368 SHA-1: 07bb2dbb339ac1fd81685728b79802e77b3e7c89 SHA-256: f846eaec28330ca031a7e16ae00993a5bf819c9bff64681654d69925bc69ee38
366 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. Specifically, the 'PDF_BASE_N_PAIR_JS_STAGER' and multiple CVE-related rules point to the use of obfuscated JavaScript. This JavaScript is recovered and decoded, and its purpose is to exploit these vulnerabilities to achieve code execution. The recovered JavaScript is likely a stager for downloading and executing a secondary payload, as indicated by the 'Pdf.Exploit.Blackhole-71' ClamAV detection.

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.Blackhole-71 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Blackhole-71
  • 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.
  • 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.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape 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.
  • 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
f199675fb64b33d09536df5a85b1ddfe3cd301ef083522b14f16ce0c4ad06476		 pdf-javascript-stream PDF /JS object 19 at offset 0x487 14573 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 5 long base64-like blob(s).
base_n_pair_stage_000.js
6d4e4782880667947cb5fee6485b4194743f85c851206aaf3ffaecbe3abe12a4		 deobfuscated-js base-31 pair decoded JavaScript at offset 0x48B 4119 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_off000047fd.icc
653b586c4707574ffcd648ba35494daed2c76ceafcf4c07d315ed961b1dc347f		 pdf-icc-profile PDF ICC profile at offset 0x47FD 408 bytes
icc_01_off00004a98.icc
2b3aa1645779a9e634744faf9b01e9102b0c9b88fd6deced7934df86b949af7e		 pdf-icc-profile PDF ICC profile at offset 0x4A98 3144 bytes

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