Emotet — Office (OOXML) / .XLSX malware analysis

Static analysis result for SHA-256 15116cf9bba79262…

MALICIOUS

Office (OOXML) / .XLSX

237.9 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2022-03-11
MD5: d5c077bbbc57fc273dbaa0727341b97c SHA-1: ec9344c41edff54fceda55a2e2e59602890a5695 SHA-256: 15116cf9bba7926250856d7e85554facf8e11d31ef78211e2c92af818f464dee
120 Risk Score

Malware Insights

Emotet · confidence 95%

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

The file was detected as malicious by ClamAV with the signature 'Xls.Downloader.Emotet-OOXML_XL-af43432fbcb8603c-9980048-0', indicating it is likely an Emotet downloader. Static analysis revealed the presence of Excel 4.0 macro sheets, which are commonly used to execute malicious code. These macros are likely responsible for downloading and executing a secondary payload.

Heuristics 2

  • 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.
  • ClamAV: Xls.Downloader.Emotet-OOXML_XL-af43432fbcb8603c-9980048-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-OOXML_XL-af43432fbcb8603c-9980048-0

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.bin
746c09de869abf9bb2740239d7cc17f7470ed11fe5b974907b1e8d1c3fc94269		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.bin 2474 bytes
xlm_sheet_01.bin
294fba96533e16b8e32fcc670b890c44fe9dfc759e5d84743c74026ba7bd4a20		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.bin 428 bytes
xlm_sheet_02.bin
f0daf3cbff097906d4170f35f5f5c2394e9b70d2a487782035c708617ae7b9ec		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.bin 428 bytes

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