Malicious PDF — malware analysis report

Static analysis result for SHA-256 83f5f410cdd3f722…

MALICIOUS

PDF

15.0 KB Created: 2009-06-06 12:30:26 +03:00 Authoring application: NitroPDF 6.0 (via BCL easyPDF 6.00.20)
MD5: 4c9d03ed46a669748e16c081985ef6bd SHA-1: a9c90850d31e0e0305a6b16de62cb401026c63af SHA-256: 83f5f410cdd3f722539030519cdcf8623727685f62f3dc25e016255e4b67af72
574 Risk Score

Malware Insights

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

This PDF file contains heavily obfuscated JavaScript that exploits multiple known vulnerabilities in Adobe Reader, specifically CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. The script is designed to download and execute a second-stage payload from the URL http://66.225.211.98/~kheyar/been/string/www/getexe.php. The presence of multiple exploit CVEs and a clear download URL indicates a malicious downloader.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 16

  • 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.
  • Multi-CVE Adobe Reader JavaScript exploit kit critical PDF_ADOBE_READER_MULTI_CVE_JS_KIT
    One recovered JavaScript stage contains multiple version-gated Adobe Reader exploit branches. This is stronger evidence than independent API keywords: the PDF is selecting old Reader vulnerabilities by viewer version and running heap-sprayed Acrobat JavaScript exploit paths.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • Shuffled variable-fragment JavaScript stager high PDF_SHUFFLED_VAR_JOIN_JS_STAGER
    PDF JavaScript stores an exploit stage as many randomly named string fragments, rebuilds the fragment order through a name array and eval(join('+')), then decodeURIComponent/evals the result. The decoder requires a large variable table and only fires when the recovered stage contains concrete Acrobat exploit JavaScript.
  • Generic recovered JavaScript exploit stage high PDF_GENERIC_STAGE_RECOVERY
    Bounded static stage recovery exposed hidden JavaScript through generic transforms such as null-byte collapse, percent decoding, marker replacement, arithmetic character codes, fromCharCode, numeric arrays, numeric-array minus-key decoders, alphabet-index arrays, /Producer half-difference metadata arrays, hex literals, marker-stripped Base64 literals, custom 6-bit XOR table decoders, or repeated-marker hex carriers. This rule is emitted only when the recovered stage contains exploit-like Acrobat JavaScript or shellcode markers.
  • 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.
  • PDF paints image(s) but contains no text operators info PDF_IMAGE_ONLY_LURE
    PDF has 1 image XObject(s) and the content stream contains no text-emitting operators (BT/ET, Tj, TJ, ', ") in either raw bytes or decompressed streams — this is the screenshot-as-PDF pattern used to bypass text-based scanners and to deliver instructions purely through rendered pixels. It is informational unless paired with invisible links or risky URI context.
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PSEOF. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://66.225.211.98/~kheyar/been/string/www/getexe.php
    • http://66.225
    • http://66.225.211

Extracted artifacts 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0015_000.js
ac7eb4cff8758c39a5cd7feec4f200d5c449a0ba3e686ec676cde4bc72d89480
pdf-javascript-stream PDF /JS object 15 at offset 0x315 29145 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
shuffled_var_join_stage_000.js
f5f5c35263636f40bd5d6185d65164715bda91044eb24f11918848dc48f714a0
deobfuscated-js shuffled variable-fragment join decoded JavaScript object 15 at offset 0x4BCD 5086 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 7 eval/decoder/string-building token(s).
shuffled_var_join_stage_001.js
76eca3f0c54b7abce5e043d3e9422effe3b6ce2f474dfa73890bf0ac4de9e351
deobfuscated-js shuffled variable-fragment join decoded JavaScript object 15 at offset 0x4425 5468 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 6 eval/decoder/string-building token(s).
shuffled_var_join_stage_002.js
805993c1545e9938ae5619a75216004e1848856c805eb8bffc299ff5ed45fe49
deobfuscated-js shuffled variable-fragment join decoded JavaScript object 15 at offset 0x4425 5082 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 7 eval/decoder/string-building token(s).
generic_stage_recovery_000.js
4fced130c6ead43d48d7026f24cb1d8cf6a4313aa586993ab5d62700c41fa895
deobfuscated-js generic stage recovery percent-decode from JavaScript object 15 at offset 0x315 27185 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s).
generic_stage_recovery_001.js
3d9e32b3a054962915e531a26b1739a495fc19797699e8f73d71333fb4551a64
deobfuscated-js generic stage recovery percent-decode -> percent-decode from JavaScript object 15 at offset 0x315 27183 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s).