Malicious PDF — malware analysis report

Static analysis result for SHA-256 0013ba27e4b2d741…

MALICIOUS

PDF

4.0 KB
MD5: 4b494124171e0af4211a125fb9ff6cfe SHA-1: f6b7ac727f320b765de40e916e9767fae22f4e69 SHA-256: 0013ba27e4b2d741f13c0e3734da609eef254be94f052a05a87628385a4488c4
258 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1071.001 Web Protocols

This PDF file contains JavaScript that exploits CVE-2008-2992, leveraging eval() and String.fromCharCode() to decode and execute a malicious payload. The deobfuscated JavaScript attempts to download a second-stage payload from the URL http://74.63.216.74/~rastafar/load.php, indicating a downloader or initial access mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 9

  • 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)
  • 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://74.63.216.74/~rastafar/load.php

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0013_001.js
96e59861bd51d9411ff2209c3dedd2bbacc1f83fd464d8d8c190e6e966bb8b6f
pdf-javascript-stream PDF /JS object 13 at offset 0x368 6229 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
ceb273040ccdc3c6b942b6c15f717e10a695cf7c0f62f49ed6fb17a8ff1d5295
deobfuscated-js PDF AcroForm base64 (decompressed) at offset 0x99D 3517 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
custom_b64_stage_000.js
ea858a24695f8b0d4a667a85e5c4657bfea1de6581569cbd4fb87cef2448ba42
deobfuscated-js custom Base64 decoded JavaScript layer 2 (PDF /JS object 13) at offset 0x95E 2019 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).