Office (OOXML) / .XLSM malware analysis — malicious · 01e8a7c53dc120fa

MALICIOUS

Office (OOXML) / .XLSM

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

MD5: d6c1b30e58fee38dc331aa4c51262087 SHA-1: 258bb630a0cec8ae599f46bc88c1cb27971ff97b SHA-256: 01e8a7c53dc120faefe6d75c59d490f49927a2e42f67cac7d272290d8ae53321

130 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample is an XLSM file containing Excel 4.0 macros. These macros utilize dangerous functions like FOPEN, FWRITE, and EXEC to construct and execute a VBScript payload. The script appears to be designed to download and run a second-stage payload from a constructed path, likely C:\ProgramData\gt\pk\rgUoHBU.vbs.

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` `d63a8437a471dd3b1847766931379595aba1cac89db21fa7c588d9e5ca98dda7`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet1.xml	6025 bytes

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