Qbot — Office (OOXML) / .XLSX malware analysis

Static analysis result for SHA-256 ce5d635837efb4ad…

MALICIOUS

Office (OOXML) / .XLSX

333.2 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2022-02-28
MD5: 8e24f7edbc5e1d120071915357998538 SHA-1: 242c5b757a86d30b85d0a7cdbb1900bf2eb43b59 SHA-256: ce5d635837efb4ad2a28965222fcc257df14f916a65de8e267cac5a0ced735be
180 Risk Score

Malware Insights

Qbot · confidence 95%

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

The sample is identified as malicious by ClamAV with the signature Xls.Downloader.Qbot-aa2a2a3fd5f4342a-9950245-0. It contains multiple Excel 4.0 macro sheets, indicating a macro-based execution. The macros appear to be responsible for downloading a second-stage payload from the IP addresses found within the script. Specifically, the script contains strings that reconstruct URLs such as '146.19.170.74/', '51.195.37.137/', and '111.90.147.222/', which are likely used for the payload download.

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.Qbot-aa2a2a3fd5f4342a-9950245-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Qbot-aa2a2a3fd5f4342a-9950245-0

Extracted artifacts 13

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.bin
5fb5a9e6ec1dacc189efcc6a68093d9b5c376b223dcb27f862984427d2aac0e2
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.bin 363 bytes
xlm_sheet_01.bin
9240857c038d474bda71d25a9bdc03e9bd845927780c5c30c8ad2d215fc30299
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet2.bin 918 bytes
xlm_sheet_02.bin
37305deb6977106275d104f5826c9a1ae694574dcf133bc8f0a88e69659fa5d9
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.bin 2263 bytes
xlm_sheet_03.bin
d795a42e7dfb9f3b384d1e5d47d879eee778b9da4bf4a945b3272471187b3422
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet3.bin 1703 bytes
xlm_sheet_04.bin
93c463343ef7f1e9e791647d561f007c38659ae4a327b3ebb864f048f16a58f6
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet4.bin 659 bytes
xlm_sheet_05.bin
4d4dd95373ceffcdeae0a74dfa09b90bd3ce229ab64dd70c7fe0f05e5b469bbd
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet5.bin 648 bytes
xlm_sheet_06.bin
8d957f41705fc5da60f409cd3c460bdb601935e6214bf78485f23a85cb252024
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet6.bin 622 bytes
xlm_sheet_07.bin
000bc8d70715fdc1e9f90bbf8ea8d827eb7d942c3f16b2c5b6d16539d6622ba7
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet7.bin 446 bytes
xlm_sheet_08.bin
104ea4dd6393a2e7568a3476bef8861dc03f02ff70847c1579759679f5b37241
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.bin 843 bytes
xlm_sheet_09.bin
617d9277b8cae5e22b22f75d36f1c1410a208c497dfd9b1fc50732ce8b8e39ba
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet8.bin 423 bytes
xlm_sheet_10.bin
fe57f943858a8919ed6e91709a3b6f572e0ddbcba21b32c8fbf3c96821baa7a0
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet3.bin 748 bytes
xlm_sheet_11.bin
93ba72b98161dad073a1ddc9f87bed6380b6a369d49aed308df35146fe953084
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet4.bin 748 bytes
xlm_sheet_12.bin
2bd138650fa507a83c5a96a8b7ece29759f24ed721eaf50eae3ada328413aacb
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet9.bin 423 bytes