Malicious PDF — malware analysis report

Static analysis result for SHA-256 fd7865b74b8b41c0…

MALICIOUS

PDF

2.1 KB
MD5: 08bdbceadbc0e30a34cbf719b89cf104 SHA-1: 9c20738827851396b554ca347c92d2cb2619395d SHA-256: fd7865b74b8b41c06cf55861563037deef4531036d6ca8fd74d40522d0c39429
106 Risk Score

Malware Insights

MITRE ATT&CK
T1027 Obfuscated Files or Information T1204.002 Malicious File: Malicious JavaScript

The PDF file contains embedded JavaScript, which is heavily obfuscated using eval() and unescape() calls. This obfuscated script, named 'javascript_obj111611_000.js', is designed to execute arbitrary code. The primary function appears to be downloading and executing a secondary payload, indicated by the suspicious JavaScript execution and obfuscation techniques. Due to the heavy obfuscation, the exact payload and delivery mechanism cannot be definitively determined, leading to a lower confidence score.

Heuristics 6

  • 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)
  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj111611_000.js
9864171cc4152f5d3e5671809dd40cebe1cf9319d0b8bfb0abd003cff50482db
pdf-javascript-stream PDF /JS object 111611 at offset 0x739 332 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).