Malicious PDF — malware analysis report

Static analysis result for SHA-256 36df77d0ab2c279e…

MALICIOUS

PDF

403.5 KB Created: 2023-01-20 05:53:31 -08:00 Authoring application: iTextSharp’ 5.5.13.2 ©2000-2020 iText Group NV (AGPL-version)
MD5: 8abe34eb390f89558bc6bcab23b9d2b5 SHA-1: c98f9ff7aac1c0247fa8ddaba8bea36acbf82ac5 SHA-256: 36df77d0ab2c279ed32196e481b7475fd361e0646a14f37c253f0790327d88ce
170 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell T1204.002 Malicious Link

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It employs invisible and repeated links to deliver a payload, specifically a ZIP archive from a Google Cloud Storage URL. The PDF structure itself contains no readable text, relying solely on these links to trick the user into downloading the malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8804

Heuristics 4

  • Invisible/repeated PDF links deliver payload file critical PDF_REPEATED_PAYLOAD_LINK_LURE
    PDF uses invisible link annotations and points to a direct payload download. Repeated invisible links or lure-like payload names such as document/unlock/verify archives match malware-delivery PDF carriers where the page is only a prompt and the real payload is fetched from the linked URL.
  • ClamAV: Pdf.Trojan.IcedID-9983376-2 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Trojan.IcedID-9983376-2
  • 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 URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://firebasestorage.googleapis.com/v0/b/ferrous-plating-371721.appspot.com/o/GsU4jkla60%2FDocument_72.zip?alt=media&token=957653c3-f610-455d-9b30-a289c7a72dfc