Malicious PDF — malware analysis report

Static analysis result for SHA-256 eb87dd7f699728af…

MALICIOUS

PDF

22.4 KB Created: 2011-72-51 03:25:00 Authoring application: String.fromCharCode
MD5: 5c5aab5dcd81cf3a7ef484d5c9d4d53b SHA-1: cdab1b7163ebead4381882e1e0066e1682a7e11f SHA-256: eb87dd7f699728af71561917d5025321b310fef2a50710130c50ea57b3dd6270
66 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 Command and Scripting Interpreter: PowerShell

The PDF document contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT and PDF_JS. The JavaScript stream utilizes String.fromCharCode and an eval() call, suggesting obfuscation and dynamic code execution. The primary function of the script appears to be downloading and executing a second-stage payload, as evidenced by the high-confidence PDF_EVAL heuristic. The extracted artifact javascript_obj0001_000.js is also suspicious.

Heuristics 5

  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (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.
  • 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_obj0001_000.js
e9ae599db516043a2be2d610b13a281e4e7ac74b1fb5cda8687444fc1c7498a6
pdf-javascript-stream PDF /JS object 1 at offset 0xA 523 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).