Malicious PDF — malware analysis report

Static analysis result for SHA-256 523553162cdb256f…

MALICIOUS

PDF

37.7 KB
MD5: 138735f289e6cf4f43e730b366da78ee SHA-1: f1a86dc70644c3dd6a7818056d384bcbde4ce641 SHA-256: 523553162cdb256f9faecb650a3278f01e42ac2546d70a9e051b4e0527587d9c
124 Risk Score

Malware Insights

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

The PDF file exhibits multiple indicators of malicious activity, including embedded JavaScript and a Flash object. The ML classifier strongly flagged this PDF as malicious. The presence of embedded JavaScript, specifically the file 'javascript_obj0006_000.js', suggests an attempt to execute code within the user's environment, likely for further exploitation or payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 7

  • RichMedia (Flash) high PDF_RICHMEDIA
    PDF contains /RichMedia (Adobe Flash) which is a historic exploit vector
  • ASCIIHexDecode filter (with exploit indicators) medium PDF_FILTER_HEX
    Hex-encoding filter present alongside exploit delivery indicators — often used to hide payload or shellcode bytes
  • 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.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
Adobe.swf
ce5f7936cf8e3536a88a804ce2d6902022df1794fa878bdc64a26866e34ba989
pdf-embedded-file PDF EmbeddedFile object 16 at offset 0xAB9 55839 bytes
javascript_obj0006_000.js
ea1181085dab4d2285f7d1aa7425dc118e1be851e0c4f60552c3b177c127c4d5
pdf-javascript-stream PDF /JS object 6 at offset 0xF5 1552 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).