Qbot — Office (OOXML) / .XLSX malware analysis

Static analysis result for SHA-256 a50fe17b8033af32…

MALICIOUS

Office (OOXML) / .XLSX

266.7 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2022-03-03
MD5: 20517496cf2ad748adbd0aa4cb7e58c5 SHA-1: d001904d7967c5014f751dcb974970db21d1d723 SHA-256: a50fe17b8033af32822f5ebff53aeb28ddea88b573882dabf64e12897461feb2
180 Risk Score

Malware Insights

Qbot · confidence 95%

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

The sample is identified as a Qbot downloader by ClamAV. It contains multiple Excel 4.0 macro sheets, which are known to be used for malicious purposes. The macros appear to be responsible for downloading a second-stage payload from one of the embedded URLs, such as '66.70.218.62/'. This activity aligns with the typical behavior of Qbot, which often uses macro-enabled documents to distribute its malware.

Heuristics 3

  • Excel 4.0 macro sheet (13 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.Qbot02221-9940029-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Qbot02221-9940029-0

Extracted artifacts 13

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.bin
abe94e3358b064225cd35e13335d3c334eebbd1438c5d12e3c12caa357826037
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.bin 363 bytes
xlm_sheet_01.bin
5d0ce14c3f9a410a20b079f5175ac639f2be6a9b4e2718d3de0e120723e3fd4a
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet2.bin 1013 bytes
xlm_sheet_02.bin
2610ce338807d07de82683c04e4585f179a1011858069759526f1028c78e127f
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.bin 2264 bytes
xlm_sheet_03.bin
3fa3f24171c7e698f3600514e899702bba37292df5746435ef294abec83b938c
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet3.bin 1795 bytes
xlm_sheet_04.bin
b04568c4d74cb58cfcba108c939ede21ce1deea7e90e913caf13e4bdd44f9daa
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet4.bin 607 bytes
xlm_sheet_05.bin
a91e9957aa9803ba690894a25123b7ffbc11d6a4af79e45d934ac611641c14a4
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet5.bin 696 bytes
xlm_sheet_06.bin
7e2013a8a735b83f5eb41d39fef4da711d78e679591e57d84d75df76a41fb8a6
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet6.bin 662 bytes
xlm_sheet_07.bin
b4e9ad4d5203a02e6b30882c0cfe414be6a65612291bbdf1e06df7f5c529086a
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet7.bin 472 bytes
xlm_sheet_08.bin
05a356abe3f9ab9d1a6e6e7c745f57cfde0d1029c2262d0bebf683b9ed7a9212
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.bin 783 bytes
xlm_sheet_09.bin
914dfba23a7afbf30975ba85827c6a66c8cd3e4e9a5b5630c1319623249e1ab5
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet8.bin 423 bytes
xlm_sheet_10.bin
9535957a89170d707174b1c9f2ef120535b96b9d620b6fdb17033f593fd01983
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet3.bin 708 bytes
xlm_sheet_11.bin
e09e1d6288c340ea05801a4c666d8334de47c01a4a1641441153f49dcf24ea31
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet4.bin 708 bytes
xlm_sheet_12.bin
fedac50f44fd24788b438c856a0bd0f9569851681124e693e8a42e722fd5c85e
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet9.bin 423 bytes