Malicious PDF — malware analysis report

Static analysis result for SHA-256 71130bb9ae1e5d25…

MALICIOUS

PDF

5.1 KB Created: 2008-08-06 01:42:27 Authoring application: Scribus 1.3.3.12 (via Scribus PDF Library 1.3.3.12)
MD5: f460a6efd2ac4f568075798696803866 SHA-1: f5e7e3e22d133a28c82df02986cfffa8132d6725 SHA-256: 71130bb9ae1e5d2511a59616e6c05a1cacc482f083c9863f8a907b34abaff4d0
258 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that exploits CVE-2007-5659 (Collab.collectEmailInfo) in Adobe Reader. The script decodes and evaluates obfuscated layers, ultimately downloading a second-stage payload from the URL http://91.203.92.136/spl2/load.php?id=10822&spl=4. This indicates a client-side exploitation attempt to execute arbitrary code.

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=10822&spl=4

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0013_001.js
5a00e13410d93dde44856ccb37dedbc57861309af6f409c6c4a207253c406968
pdf-javascript-stream PDF /JS object 13 at offset 0x363 6759 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
94945ebc6537d27acfd91e87f6c89d9e7793c5e958c651fb12638be92736fc82
deobfuscated-js PDF AcroForm base64 (decompressed) at offset 0x719 4393 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
custom_b64_stage_000.js
1beab6b372bdaec1c05730cd21fcea922e62fbc971b16f18ea26eadd3448ef8b
deobfuscated-js custom Base64 decoded JavaScript layer 2 (PDF /JS object 13) at offset 0x6DA 2624 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).