Emotet Office (OOXML) / .XLSM malware analysis — malicious · b20a8dc2ba488466

MALICIOUS

Office (OOXML) / .XLSM

49.4 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2022-03-16

MD5: 8fa424bc8c1be0ffaeeaddda962cab82 SHA-1: bd6d378c42b04770df0f693711a640eb55066d4c SHA-256: b20a8dc2ba488466c0448f9a60e948c6cdff374ee7c271e5109150bcb6b1964d

250 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK

T1059.005 Visual Basic T1059.001 PowerShell T1204.002 Malicious File T1105 Ingress Tool Transfer

This XLSM file contains Excel 4.0 macros that utilize dangerous functions like FORMULA to download and execute a payload. The macros reconstruct the string 'regsver32.exe' and use embedded URLs to fetch it. The ClamAV detection and heuristic firings strongly indicate this is an Emotet downloader variant. The primary intent is to download and execute a second-stage payload from the listed URLs.

Heuristics 6

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.
Excel 4.0 Auto_Open defined name critical OOXML_XLM_AUTOOPEN_DEFINEDNAME

Workbook defines _xlnm.Auto_Open or _xlnm.Auto_Close while containing an XLM macro sheet. This is the OOXML/XLSB auto-execution shape for Excel 4.0 macros.
Dangerous XLM formula APIs: FORMULA critical OOXML_XLM_DANGEROUS_FN

Excel 4.0 macro sheet uses formula APIs that call directly into Win32 (=CALL/=EXEC/=REGISTER/=FORMULA). These are the primitives used to download payloads, write files, and start processes from an XLM macro without invoking VBA.
ClamAV: Xls.Downloader.Emotet03221-9941792-0 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Xls.Downloader.Emotet03221-9941792-0
Hidden worksheet (hidden) low OOXML_HIDDEN_SHEET

Excel workbook contains 6 hidden sheet(s) — hidden sheets are commonly used to conceal macro code, staging data, or intermediate payload construction
Embedded URL info EMBEDDED_URL

One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
URL https://arealama.com/assets_template/58DBYXQh01ATcsKY/
- http://antaoco.com/wp-admin/QpyjXPLrEXf3R9/
- http://www.automatic-taps.com/Templates/TyJj6dRjzqE/
- http://arkamani.net/administrator/KIZXGmaRTF6N3qQqH/
- https://www.artificium.es/blogs/mu8yHJ/
- https://www.manchesterot.co.uk/about-us/fxVCCMDni/
- http://www.atara.com.tr/Template/595vJ91nQx/
- http://schemas.openxmlformats.org/spreadsheetml/2006/main
- http://schemas.microsoft.com/office/excel/2006/main
- http://schemas.openxmlformats.org/officeDocument/2006/relationships
- http://schemas.openxmlformats.org/markup-compatibility/2006
- http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac
- http://schemas.microsoft.com/office/spreadsheetml/2014/revision
- http://schemas.microsoft.com/office/spreadsheetml/2015/revision2
- http://schemas.microsoft.com/office/spreadsheetml/2016/revision3
- http://schemas.microsoft.com/office/spreadsheetml/2016/revision6

Extracted artifacts 3

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`xlm_sheet_00.xml` `561bd2ad03d5ff349d3a0a4fbda71b956dd8d97a0dbce4e25549bf8a7721c5df`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml	4049 bytes
`xlm_sheet_01.xml` `4f892349a6f0ce9450df5d764f02eea0a737d43225bc39e0b3e39eaafe266901`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet1.xml	1276 bytes
`xlm_sheet_02.xml` `f8dcec9dac216a8c4fc7140768d73598afe199c381abfb2f58ad13ed8f5733f6`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet2.xml	1152 bytes

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