Malicious PDF — malware analysis report

Static analysis result for SHA-256 fd171a31032f0ebc…

MALICIOUS

PDF

4.7 KB Authoring application: Fogohadodavejiqa (via b2a88Jigisewoue)
MD5: c2ff7035f6d53b68c85f09c7a7ee97bc SHA-1: aa9983e90664ca07ce203c4debd7e2d666a2e0f5 SHA-256: fd171a31032f0ebc67cb6431e40ccd7c8f669263a2f249207665e73527e27385
128 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF contains obfuscated JavaScript, indicated by multiple heuristic firings including 'PDF_JAVASCRIPT', 'PDF_JS', 'PDF_EVAL', and 'PDF_PAGE_WORD_XOR_EVAL_STAGER'. The ML classifier also strongly flagged this PDF as malicious. The embedded JavaScript file, 'javascript_obj0010_000.js', is likely responsible for downloading and executing a second-stage payload, a common technique for initial access.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • Page-word XOR JavaScript eval stager high PDF_PAGE_WORD_XOR_EVAL_STAGER
    PDF JavaScript enumerates rendered page words with getPageNthWord/getPageNumWords, extracts encoded byte fragments, XOR-decodes the stage with char-code helpers, and evals the result. This is an old exploit-kit staging pattern and is not normal document JavaScript.
  • 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.
  • 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_obj0010_000.js
f927d745a5f88bd25577c1ca5989364febb11ae7e2090c66669d4b594919741c
pdf-javascript-stream PDF /JS object 10 at offset 0xDE7 496 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).