Malicious PDF — malware analysis report

Static analysis result for SHA-256 376df3032a953ac1…

MALICIOUS

PDF

29.0 KB Created: 2011-72-51 03:25:00 Authoring application: String.fromCharCode
MD5: 93970bc253425521a2678bce151d8d25 SHA-1: 5dd3064dbdcf4345832516b4aa5d6412c14927c0 SHA-256: 376df3032a953ac1d7cf87e24cfa36cee9d4b6005403b952965aafdbeff61573
106 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, indicated by the PDF_JAVASCRIPT and PDF_JS heuristics. The PDF_METADATA_EVAL_STAGER and PDF_EVAL firings suggest that the JavaScript is obfuscated and uses eval() to execute, a common technique for downloading and running additional malware. The use of String.fromCharCode further supports the obfuscation. No specific family could be identified, but the overall pattern points to a downloader.

Heuristics 6

  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • PDF metadata JavaScript eval stager high PDF_METADATA_EVAL_STAGER
    PDF JavaScript reads document metadata fields such as title, subject, or producer, decodes character data with parseInt/String.fromCharCode style helpers, and evals the recovered stage. This is a high-signal exploit-kit staging pattern.
  • 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
7dda5b718d69599589ffe368a441dcfd7f307cdc44ba296e70cafd03678e9089
pdf-javascript-stream PDF /JS object 1 at offset 0xA 611 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s).