Malicious PDF — malware analysis report

Static analysis result for SHA-256 0a815b1aa16b4fe2…

MALICIOUS

PDF

22.3 KB Created: 2012-09-17 23:33:20 +04:00 Authoring application: Adobe Acrobat 10.0 (via Acrobat Web Capture 10.0)
MD5: b4fc3ab4031225683c41434585f9a070 SHA-1: cb2c2c4c2d72dee901bd033e4a23df2c9f0b0fdb SHA-256: 0a815b1aa16b4fe255c461e0f356a35e216e10fe542ff55752e8bbaea889e2a2
558 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF sample contains obfuscated JavaScript that exploits multiple CVEs (CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, CVE-2008-2992) to download a second-stage payload. The deobfuscated JavaScript explicitly contains the URL http://adds.kbleisnerresourcestaffing.info/stats/inferior/attempted-searching.php?ellqi=1f:1i:1i:32:1h&sfdth=1g:2w:33:1l:32:1i:31:1k:1o:1i&eqkhg=1h&rkwtqb=ahp&sfczck=azfwfid, indicating a clear intent to fetch and execute further malicious code.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 14

  • 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)
  • Pidief-style multi-CVE JavaScript dispatcher critical CVE likely PDF_PIDIEF_MULTI_CVE_DISPATCH
    A single JavaScript body branches on app.viewerVersion and invokes two or more of the canonical Reader sinks (Collab.collectEmailInfo, Collab.getIcon, util.printf with a field-width format string). This is the 2009-2010 Pidief.J multi-exploit landing template: a per-version dispatcher that fires the matching CVE chain for whichever Reader version opens the file.
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
  • 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.
  • PDF JavaScript shellcode contains an embedded download URL high PDF_JS_SHELLCODE_DOWNLOAD_URL
    Decoded PDF JavaScript shellcode contains a hardcoded http(s) URL stored as little-endian %uXXXX Unicode escapes. Reader exploit shellcode embeds the second-stage fetch URL this way and pulls it down with a urlmon/URLDownloadToFile-style download-and-execute (commodity downloader behaviour rather than a specific Acrobat CVE).
  • 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://adds.kbleisnerresourcestaffing.info/stats/inferior/attempted-searching.php?ellqi=1f:1i:1i:32:1h&sfdth=1g:2w:33:1l:32:1i:31:1k:1o:1i&eqkhg=1h&rkwtqb=ahp&sfczck=azfwfid
    • http://adds.kbleisnerresourcestaffing.info/stats/inferior/attempted-searching.php?wwgsdfea=1f:1i:1i:32:1h&mcncuabj=1g:33:1g:1i:2v:1j:1g:32:1j:30&xvinsxom=1h&gehz=dnamuox&lrahkru=mlsnpu
    • 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/
    • http://www.iec.ch

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0019_000.js
a1ab1737ce8e7b231405c2c681ed97a605b1eb048767f3dadc7b1586d450eaf8
pdf-javascript-stream PDF /JS object 19 at offset 0x487 10590 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
663384db10e9da588a08016b263638c32aa66f2e6dded8a5a254e8a1a129f3ae
deobfuscated-js base-31 pair decoded JavaScript at offset 0x495 4779 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_off000034a4.icc
653b586c4707574ffcd648ba35494daed2c76ceafcf4c07d315ed961b1dc347f
pdf-icc-profile PDF ICC profile at offset 0x34A4 408 bytes
icc_01_off0000373f.icc
2b3aa1645779a9e634744faf9b01e9102b0c9b88fd6deced7934df86b949af7e
pdf-icc-profile PDF ICC profile at offset 0x373F 3144 bytes