Malicious PDF — malware analysis report

Static analysis result for SHA-256 6e9202a8a3f10138…

MALICIOUS

PDF

5.2 KB Created: 2008-08-06 01:42:27 Authoring application: Scribus 1.3.3.12 (via Scribus PDF Library 1.3.3.12)
MD5: bb8e81ab9ebe9d46488e2c37da88189a SHA-1: e53b707697acf8a624bab4dc385be1c8b0e4de94 SHA-256: 6e9202a8a3f10138d54b08d64c8b8b9f1fc88ef00d2477bddf930713dc5e5120
258 Risk Score

Malware Insights

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

The PDF file contains obfuscated JavaScript that leverages the CVE-2007-5659 vulnerability (Collab.collectEmailInfo) to execute arbitrary code. This script decodes and evaluates further layers of JavaScript, ultimately downloading a payload from the URL http://91.203.92.136/spl2/load.php?id=282&spl=4. The ML classifier strongly indicates maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 9

  • 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)
  • 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.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • 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. (matched inside decoded stream)
  • 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://91.203.92.136/spl2/load.php?id=282&spl=4

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0013_001.js
21bc038a0f4c38bc88c822c13e3a1ada956dd802dcefabf5dbd35058066870ab
pdf-javascript-stream PDF /JS object 13 at offset 0x364 6844 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
acroform_b64_00.js
bdf086ddd37145cad89f1e539d9b66cd857a9d04b8c186c50e6fe96224b0374a
deobfuscated-js PDF AcroForm base64 (decompressed) at offset 0x71B 4458 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 4 long base64-like blob(s).
custom_b64_stage_000.js
3dde3b9b2485279fd03bc297d02bd8e5e84379ae48eff51357e96680fc6b8c6c
deobfuscated-js custom Base64 decoded JavaScript layer 2 (PDF /JS object 13) at offset 0x6DC 2610 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).