Qbot — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 d4344061c4a95e9a…

MALICIOUS

Office (OLE) / .XLS

88.0 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2021-11-07
MD5: 26623df40bda7112918ed3d011aeb344 SHA-1: 2740ab866fc3d0779dfcab5cd348c54d962a3e04 SHA-256: d4344061c4a95e9a84ef57e55cf2501a0ba1df913def56d743c5cbe671cfd898
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 is an Excel 4.0 macro-enabled spreadsheet containing an Auto_Open macro. This macro is designed to execute dangerous functions, specifically to download a payload from one of the three embedded URLs. The ClamAV detection and heuristic firings strongly indicate this is a Qbot downloader.

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: Xls.Downloader.Qbot1120210-9905989-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Qbot1120210-9905989-0
  • 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://sco.com.br/dPB0iPit6f8/b.html
    • https://brunodinizitatiaia.com.br/eHOVauZU/b.html
    • https://soccer-assist.co.uk/57IsaduJ/b.html

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
e6d2835fda5103c005d6191e198ff585c22aa8c15a987044f14d8fa717ecff1e
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 11131 bytes