Office (OOXML) / .XLSM malware analysis — malicious · e49f8b68c3af361f

MALICIOUS

Office (OOXML) / .XLSM

108.2 KB Created: 2021-10-27 10:31:49 UTC Authoring application: Microsoft Excel 12.0000

MD5: c8c40aa81d28f93c409ac38b80684219 SHA-1: fee1cfc7aceda3248932aca53731000f86c1e4c4 SHA-256: e49f8b68c3af361ffba2d29f227192bb2bb2ea10132dbdea7f95d408b8c3f7a9

130 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1059.001 PowerShell T1105 Ingress Tool Transfer

This XLSM file contains Excel 4.0 macros that leverage dangerous functions like FOPEN, FWRITE, and CHAR to construct a VBScript payload. The script is written to 'C:\ProgramData\jDaYZnaovrTW e.vbs'. The use of these functions indicates an attempt to download and execute a second-stage payload, which is a common technique for malware delivery.

Heuristics 4

Excel 4.0 macro sheet (1 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.
Dangerous XLM formula APIs: FOPEN, FWRITE, FCLOSE, EXEC, RETURN 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.
Hidden worksheet (hidden) low OOXML_HIDDEN_SHEET

Excel workbook contains 1 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 http://schemas.openxmlformats.org/spreadsheetml/2006/main
- http://schemas.microsoft.com/office/excel/2006/main
- http://schemas.openxmlformats.org/officeDocument/2006/relationships

Extracted artifacts 1

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`xlm_sheet_00.xml` `0d01a877738cbeccace8765eaee0878f878f25f66cbed975e4c915d4596838f8`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet1.xml	5431 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.