Malicious PDF — malware analysis report

Static analysis result for SHA-256 2543aba2a3948c5b…

MALICIOUS

PDF

36.8 KB Created: 2010-02-04 19:00:52 +03:00 Authoring application: formTookYou (via e4f037a7b0481cac2b28293cd99a559f)
MD5: fdb65842a319ce416318a9fbef97bcf4 SHA-1: ca2be013cc1f87954dbc656a30e340c16d4f4b29 SHA-256: 2543aba2a3948c5b067ab38420719eab04306d69890233b0b6a47dbbb09d3356
64 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF contains embedded JavaScript and triggers an action via an Optional Content Group, indicating a malicious intent to execute code. The ML classifier strongly supports this assessment. The JavaScript is likely responsible for downloading and executing a second-stage payload, although the exact mechanism is obscured by obfuscation and truncation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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.
  • ASCII85Decode filter (with exploit indicators) low PDF_FILTER_85
    ASCII85 encoding filter present alongside exploit delivery indicators — uncommon outside of obfuscation
  • 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
  • PDF paints image(s) but contains no text operators info PDF_IMAGE_ONLY_LURE
    PDF has 1 image XObject(s) and the content stream contains no text-emitting operators (BT/ET, Tj, TJ, ', ") in either raw bytes or decompressed streams — this is the screenshot-as-PDF pattern used to bypass text-based scanners and to deliver instructions purely through rendered pixels. It is informational unless paired with invisible links or risky URI context.