Qbot — Office (OLE) / .XLSX malware analysis

Static analysis result for SHA-256 da6a206ae1ea506f…

MALICIOUS

Office (OLE) / .XLSX

105.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel
MD5: 637480408eb715add3ae1c1fedecb360 SHA-1: 4a5905af0bc57583912842d0ba5d615b4c984496 SHA-256: da6a206ae1ea506fb5d0eb7bed97b0381bbb28cc3f4a8a137034e1a5f27777e7
262 Risk Score

Malware Insights

Qbot · confidence 95%

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1204.002 Malicious File Execution: Malicious File

The file contains Excel 4.0 macros, specifically an Auto_Open macro, which is a known technique for executing malicious code. The macros reconstruct and attempt to download payloads from three distinct URLs: "http://dongarza.com/gJW5ma382Z/x.html", "http://headlinepost.net/3AkrPbRj/x.html", and "http://produtoratimedeelenco.com.br/9E6Y322u/x.html". ClamAV detection confirms this is a Qbot downloader. The reconstructed URLs are added as IOCs.

Heuristics 6

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • URL reconstructed from XLM cell array (3 URLs) critical OLE_XLM_CELL_ARRAY_URL
    Excel 4.0 macro sheet stages its payload URL across the BIFF8 Shared String Table (one quoted-char SST entry concatenated with & at runtime) or across individual numeric cells (one ASCII charcode per cell). The reconstructed URL is invisible to literal-bytes URL extraction because it is never contiguous in the workbook stream. URLs were recovered by walking the BIFF8 record stream and decoding SST entries plus LABELSST/RK/NUMBER cells.
  • ClamAV: Doc.Downloader.Qbot11202120-9906200-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Qbot11202120-9906200-0
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.
  • 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://dongarza.com/gJW5ma382Z/x.html
    • https://headlinepost.net/3AkrPbRj/x.html
    • https://produtoratimedeelenco.com.br/9E6Y322u/x.html

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
2d69a468deda6ef532bccca4917aca41c7abe1a521540a9fe9f977b5d05e05bf
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 11378 bytes