Malicious PDF — malware analysis report

Static analysis result for SHA-256 2c98981030df5a6b…

MALICIOUS

PDF

6.52 MB Created: n;¿™»RÅ.È烙ÔƯ„à!ù Authoring application: Ôþû©íc–Ö&—NØ­„íç4ƒÐeÞ{†Ò.\ø!£ÉK‹Õ!ÑԐÈé;ÆÊÖæŸþÀàÒ闔³R3¢ù|¼©ÄÈh˜è—µwF L‚´ÔäaöÑoh8rè
MD5: 6fd787db8bbd55845eee040663ba53d9 SHA-1: d76a844e8d47520b0931d04d6b674984762140a8 SHA-256: 2c98981030df5a6bd84ccf8408a07c4a2fd0fb8443e6a711b08982460c440d2c
88 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 Command and Scripting Interpreter: PowerShell

The PDF file is heavily obfuscated and encrypted, with heuristics indicating the presence of embedded JavaScript. The 'PDF_IMAGE_ONLY_LURE' heuristic suggests the document is designed to trick the user into clicking on something, likely to trigger the hidden JavaScript. The JavaScript is likely responsible for downloading and executing a second-stage payload, but its exact functionality is obscured by the encryption and obfuscation.

Heuristics 4

  • Encrypted PDF carries /js — payload hidden from static analysis high PDF_ENCRYPTED_WITH_JS
    PDF declares /Encrypt and also references an executable trigger (/js). 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.
  • Unusually high stream count medium PDF_MANY_STREAMS
    PDF contains 501+ stream objects — may indicate heap spray or heavy obfuscation
  • PDF paints image(s) but contains no text operators medium PDF_IMAGE_ONLY_LURE
    PDF has 2 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.
  • 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.