Malicious PDF — malware analysis report

Static analysis result for SHA-256 0cf204cdc5525e23…

MALICIOUS

PDF

252.0 KB Created: ÌÁ¯,dUh‘^ÃÞý“|ß/,T¤H!
MD5: 259619baf3114bb4eeefaa1a97c1f939 SHA-1: 1fd2661a0308430d09e06f4bdc1a888d58c2a2ba SHA-256: 0cf204cdc5525e2337606b8e33fd6a21691afb8b4f58dae2b55289d15b53c99b
184 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains embedded JavaScript, which is used to obscure the malicious content and likely execute an exploit. The ML classifier strongly indicates maliciousness. The presence of XFA forms and JavaScript combined with encryption suggests an attempt to bypass static analysis and deliver a malicious payload, consistent with spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 8

  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
  • 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.
  • 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
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • PDF paints image(s) but contains no text operators info 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
C
0c32dee86af11fe08bceec2ed5c87d87096a46b6ba3dd4b186dd51b4cac52193
pdf-embedded-file PDF EmbeddedFile object 50 at offset 0x3B0A 2376 bytes