Bumblebee — PDF malware analysis

Static analysis result for SHA-256 91e43c044fdcad13…

MALICIOUS

PDF

102.1 KB Created: 2023-02-21 10:10:38 -08:00 Authoring application: iTextSharp’ 5.5.13.2 ©2000-2020 iText Group NV (AGPL-version)
MD5: 323ee7e3d79671befe72fe6f79f0f6b3 SHA-1: 2442ca895275f9a4bda44c18273ad6b8d6815780 SHA-256: 91e43c044fdcad13a25d772b91065f78ac7a809a57ace84a4606c4c3e92afaa2
170 Risk Score

Malware Insights

Bumblebee · confidence 95%

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

The PDF is an image-only lure designed to trick users into clicking on invisible links. These links repeatedly point to a payload URL, which is a common tactic for delivering malware. ClamAV identified the sample as Pdf.Downloader.Bumblebee, indicating it's likely a downloader for the Bumblebee malware family. The primary attack vector involves embedding malicious links within the PDF that lead to the download of a ZIP archive.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9464

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.Downloader.Bumblebee-9988748-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Downloader.Bumblebee-9988748-0
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 2 image(s), only 0 text block(s), carries a click-outward action, and is only 102 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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/tonal-depth-377622.appspot.com/o/cQtCXoljqM%2FContract_02_21_Copy%2332.zip?alt=media&token=0af57743-0613-4fa8-90c9-fd5045f227bc