Qbot — Office (OLE) / .XLSX malware analysis

Static analysis result for SHA-256 f26212597dcbc66c…

MALICIOUS

Office (OLE) / .XLSX

105.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel
MD5: 33631f62b4098d1efe0a1e5a3f84bdf9 SHA-1: f9d416281ef0ce8d337cebc695b4867371a8d6b0 SHA-256: f26212597dcbc66c2d994e4d12442d4a682d277583ebda155a25239646a36b47
262 Risk Score

Malware Insights

Qbot · confidence 95%

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1204.002 Malicious File Execution: User Execution: Malicious File T1059.001 Command and Scripting Interpreter: PowerShell

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical indicator of malicious intent. These macros are designed to execute dangerous functions, including running external code. The macros reconstruct and embed three URLs which are likely used to download and execute a second-stage payload. ClamAV detection confirms this as a Qbot downloader variant.

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

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