Qbot — Office (OOXML) / .XLSX malware analysis

Static analysis result for SHA-256 579345cf974eacc3…

MALICIOUS

Office (OOXML) / .XLSX

117.7 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2022-03-11
MD5: 96c5a960796b7c4456a70f006d55a288 SHA-1: edcc1bef6ea4563c5f9c164bb6f91cefad352d54 SHA-256: 579345cf974eacc370d6393eff16fe93a8f4dc876bf9aa952aa50f6ac316448a
180 Risk Score

Malware Insights

Qbot · confidence 95%

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

The sample is an Excel file containing multiple Excel 4.0 macro sheets, as indicated by the OOXML_XLM_MACROSHEET and OOXML_XLSB_INTL_MACROSHEET_IN_XLSX heuristics. The ClamAV detection of 'Xls.Downloader.Qbot03220-9942292-0' strongly suggests the Qbot family. The extracted macro content reveals functions like 'FileA', 'UrlMon', and 'Directory', and attempts to download content from URLs such as 'http://Z'. This indicates the macro's purpose is to download and execute a second-stage payload, consistent with Qbot's typical behavior.

Heuristics 3

  • Excel 4.0 macro sheet (12 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.Qbot03220-9942292-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Qbot03220-9942292-0

Extracted artifacts 12

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.bin
294ede1542984d5f1f1263eb2584ef46b448bf7a8e6abbc440c8793d2e7cce4d
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.bin 982 bytes
xlm_sheet_01.bin
48bcefb726800818b1ec3e8999648ef3c55cc38ed66e64f1bb4bad2c23d422ea
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet3.bin 703 bytes
xlm_sheet_02.bin
50d38e242c72bf920d3068e936450ddb6fbc05047ff6e164d1c2c79a64f657d4
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.bin 2997 bytes
xlm_sheet_03.bin
bbb7975ab842022f0808c427ff1955d2a286bc5cb79a524818fd581fb299575b
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet2.bin 1338 bytes
xlm_sheet_04.bin
2e92e3a57797ef82ce6293b25ad566ac5e7e3bb3d90bb360be34a9e9221ac984
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet3.bin 777 bytes
xlm_sheet_05.bin
543b5f79d431605307d5ececf494efed92231b068c373c20f73e66e17797fcc9
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet4.bin 703 bytes
xlm_sheet_06.bin
396f335f40b1eb504c6acdaa0658a74c667d073a82ebf346bd3835f0315031d5
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet4.bin 777 bytes
xlm_sheet_07.bin
d48d79067fcc74f9318a7436081374c5155baef7586e62262e4c36e1d25d05bf
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet5.bin 562 bytes
xlm_sheet_08.bin
f3beeaf0a81a225db880c06f58619567ae2efd6e35a2ec1cd93cf27a4e123695
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet8.bin 393 bytes
xlm_sheet_09.bin
c5c1c7d7ce3444c8fad5b636765e9e57d733d3ac6fcc74100306e91072c0f361
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet6.bin 442 bytes
xlm_sheet_10.bin
b956b926bf4f010b2889988755963f4271011fc7e55855977ead7a34320d13bb
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.bin 763 bytes
xlm_sheet_11.bin
38e7918b13a0d2ecf92d19ee736358e49e1ef3ef1764d18c9774dfedaa0d81f2
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet7.bin 393 bytes