Malicious PDF — malware analysis report

Static analysis result for SHA-256 18ba1756658eeaca…

MALICIOUS

PDF

14.8 KB Created: 2009-06-06 12:30:26 +03:00 Authoring application: NitroPDF 6.0 (via BCL easyPDF 6.00.20)
MD5: 8a4c7bacbb9c1816108ed8b8e487f5cc SHA-1: 3361fe95590f73013705fdc70a24064301cc2e88 SHA-256: 18ba1756658eeaca7e2b4ebab071f992046b027b0ad0ffbc97fc1b9fc48f3ce6
672 Risk Score

Malware Insights

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

This PDF document contains obfuscated JavaScript that exploits multiple known vulnerabilities in Adobe Reader, including 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://ogzhnsltk.com/plugins/getexe.php. The presence of multiple exploit techniques and the download URL strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 17

  • 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.
  • 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.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (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.
  • 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://ogzhnsltk.com/plugins/getexe.php
    • http://ogzhnsl

Extracted artifacts 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0015_000.js
d4fc705a67fffaf942fd8e9eace04dec6d07e817e41e9d44f5a34f5f09d392ce
pdf-javascript-stream PDF /JS object 15 at offset 0x315 28557 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
bb1e20a0a9bee1279009612d8c11ae8fc16672190659579a026796bd8d361a4d
deobfuscated-js shuffled variable-fragment join decoded JavaScript object 15 at offset 0x4A34 4942 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
6fd7795ede8680e08a0e6c2f8e43590c717e5a0b1a473a1a3b67d96259cba505
deobfuscated-js shuffled variable-fragment join decoded JavaScript object 15 at offset 0x42AC 5308 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
b53d264488fbb8aa25d6a3b56426d1331b7581d4c3fb4fad186d9d093393feca
deobfuscated-js shuffled variable-fragment join decoded JavaScript object 15 at offset 0x42AC 4938 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
8edc45ce36037c986cf90e74acb28af5eb4256580cbbbd1b7de48c0507ee02f2
deobfuscated-js generic stage recovery percent-decode from JavaScript object 15 at offset 0x315 26629 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 6 eval/decoder/string-building token(s).
generic_stage_recovery_001.js
8a6584d69b7189c706ed2b68978022e544b52832ab0966143c41c86a1d55cbce
deobfuscated-js generic stage recovery percent-decode -> percent-decode from JavaScript object 15 at offset 0x315 26627 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 6 eval/decoder/string-building token(s).