Qbot — Office (OOXML) / .XLSX malware analysis

Static analysis result for SHA-256 d74b00dde228d80e…

MALICIOUS

Office (OOXML) / .XLSX

229.5 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300
MD5: 5bbbf314b9a3de15e51ea38187c3c3c5 SHA-1: e14b9563eb241c7582dfc4cfdfdab1d960b2c5e6 SHA-256: d74b00dde228d80e09d1c2a9144216de68b8a89ac1966dacfcae8e9dc3f52738
180 Risk Score

Malware Insights

Qbot · confidence 95%

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

The file is identified as malicious by ClamAV with the signature Xls.Downloader.Qbot022213-9940035-0, indicating a Qbot downloader. The presence of Excel 4.0 macro sheets within an XLSX file is a critical heuristic firing, strongly suggesting macro-based execution. While the macro content is heavily obfuscated and truncated, the overall pattern points to a downloader designed to fetch and execute a further stage.

Heuristics 3

  • Excel 4.0 macro sheet (3 sheet(s)) critical OOXML_XLM_MACROSHEET
    Spreadsheet contains an Excel 4.0 (XLM) macro sheet — XLM was a major Office malware vector during 2020-2022 and evaded many VBA-focused controls before Microsoft tightened XLM defaults. Even legitimate XLM use is rare in modern workbooks. The macro sheet is stored as XLSB/BIFF12 binary content, which many XML-only OOXML scanners miss.
  • XLSB international XLM macro sheet hidden in .xlsx critical OOXML_XLSB_INTL_MACROSHEET_IN_XLSX
    OOXML package is named .xlsx but contains XLSB workbook parts and an international Excel 4.0 macro sheet. This hides XLM macro execution from scanners that trust the extension or only inspect XML worksheet parts. The technique is macro execution, not a document-parser CVE.
  • ClamAV: Xls.Downloader.Qbot022213-9940035-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Qbot022213-9940035-0

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.bin
f8697dc5c0d9517e96762ed8c23644a4c803e8aef37bc2fefcd0b4dab3520881		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.bin 2474 bytes
xlm_sheet_01.bin
72c6a109bf29615dd0469909a27069fef9fbea3f2a16397078a7e14813341e64		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.bin 484 bytes
xlm_sheet_02.bin
1b2f59b0ef69a5b44e2672fc66c5bfba0774aa03ceddd3096e61c17dbe8c9e84		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.bin 484 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.