Malicious PDF — malware analysis report

Static analysis result for SHA-256 24abb00b32877843…

MALICIOUS

PDF

2.1 KB
MD5: af68d76fcaf22f08a5fcfe38cf7303b4 SHA-1: 78fd3eff8322b6534ebefa2cf168d8392c000bd5 SHA-256: 24abb00b328778437ef3cfe50d67b25fbaf716b57932bcba8399dcff9a20d2f5
106 Risk Score

Malware Insights

MITRE ATT&CK
T1027 Obfuscated Files or Information

The PDF contains embedded JavaScript, which is heavily obfuscated using `eval()` and `unescape()`. The `String.fromCharCode()` function is also used, further indicating obfuscation. The primary heuristic firings point to the use of JavaScript for malicious purposes within the PDF. The extracted artifact `javascript_obj111611_000.js` is also suspicious. The script's obfuscation suggests it is designed to download and execute a second-stage payload, making the PDF a downloader.

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 0x731 332 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).