Malicious PDF / .TXT — malware analysis report

Static analysis result for SHA-256 5684f94d2132314b…

MALICIOUS

PDF / .TXT

31.4 KB Created: >¹l:ò÷›¡£Ï¹7ìÛÌ3èÓ Authoring application: »Ù Ê". ¡Åɐïþã« (via »Ù Ù". «Å̐îþï¼ðŽ)
MD5: 09d8d97c6bc298a010303ad346f368b7 SHA-1: 1e746c668324a7d5e6b55e14e1df1223c68df6ac SHA-256: 5684f94d2132314b20f6f8409599cbd46d67504ce4b50ce44bcab009814ce520
64 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF file contains embedded JavaScript, indicated by the PDF_JAVASCRIPT and PDF_JS heuristics. It is also flagged as PDF_ENCRYPTED_WITH_JS, suggesting the JavaScript is used to obfuscate or protect the main payload from static analysis. The large size of the embedded JavaScript object (29544 bytes) further supports the idea that it contains significant malicious code. The exact intent of the script cannot be determined due to its size and potential obfuscation, but it is likely designed to download and execute a second-stage payload.

Heuristics 4

  • Encrypted PDF carries /JavaScript — payload hidden from static analysis high PDF_ENCRYPTED_WITH_JS
    PDF declares /Encrypt and also references an executable trigger (/JavaScript). Document encryption hides the JavaScript body and stream contents from static scanners — combined with auto-execution indicators this is a known evasion pattern used to deliver weaponised JavaScript that the analyst cannot inspect without the decryption key.
  • 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.
  • Optional Content Group with action trigger low PDF_OPTIONAL_CONTENT
    Optional Content Group (layer) co-occurs with an action trigger — content can be selectively hidden from viewers or scanners while the action still fires on open

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0009_000.js
551d193d5e5b1ec6ddf2199e8aefa443f05f0eac69860603b21d696ea76ea28c
pdf-javascript-stream PDF /JS object 9 at offset 0x3D1 29544 bytes