Malicious Office (OOXML) / .XLSM — malware analysis report

Static analysis result for SHA-256 f75eb673f63060d1…

MALICIOUS

Office (OOXML) / .XLSM

105.5 KB Created: 2006-09-16 00:00:00 UTC Authoring application: Microsoft Excel 14.0300
MD5: e318c284205bd6df674722e362e89f84 SHA-1: 0c34215a6757d1b4f5d468e67d76d1fde572d362 SHA-256: f75eb673f63060d1a8726b6d7255555eda5873b8a95c8efcea1bb9eb61972c1f
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1059.001 Command and Scripting Interpreter: PowerShell T1204.002 Malicious Link: Malicious File

The sample is an Excel macro-enabled sheet (XLSM) containing Excel 4.0 macros. These macros utilize dangerous functions like CALL and EXEC, which are known primitives for executing arbitrary code. The document body contains multiple URLs that are likely intended to host and download a second-stage payload. The presence of these functions and URLs strongly suggests an intent to download and execute a payload, characteristic of a downloader malware.

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.
  • 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: CALL, EXEC, FORMULA.FILL, HALT 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.
  • 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
    • http://schemas.openxmlformats.org/markup-compatibility/2006
    • http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.xml
1ac8164566eb69dad25e2fb55eafdc9b2a3eac004a1f0cc291930400a77c99df		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 230169 bytes

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