Office (OOXML) / .XLSX malware analysis — malicious · ca1e4da51d6a0208

MALICIOUS

Office (OOXML) / .XLSX

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

MD5: c0c0a0a10c0deb13aae2414b729f0ca4 SHA-1: 5a076347b93fe07829339bf8ac0739b2e7d704e5 SHA-256: ca1e4da51d6a020860d471be5eaa72b2f644501086ec1ef0bf565ee83d4b05c6

60 Risk Score

Malware Insights

MITRE ATT&CK

T1059.001 PowerShell T1204.002 Malicious File

The sample is an Excel 4.0 macro sheet, a known vector for malware delivery. The embedded macro uses WMIC to execute a file named 'excel.rtf' from the ProgramData directory. This indicates the macro's intent is to download and execute a second-stage payload. The specific family is not identifiable from the provided evidence.

Heuristics 1

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. The macro sheet is stored as XLSB/BIFF12 binary content, which many XML-only OOXML scanners miss.

Extracted artifacts 1

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`xlm_sheet_00.bin` `54b64267ea3dfb36573b20653802b05d9941bcc0e4134a125365ec7a88143d57`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet1.bin	167910 bytes

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