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

Static analysis result for SHA-256 ad2c8ad529c03212…

MALICIOUS

Office (OOXML) / .XLSM

39.2 KB Created: 2020-05-17 14:23:36 UTC Authoring application: Microsoft Excel 16.0300
MD5: 7d9c1aef3de36111c91c5f508409906d SHA-1: b5a2711f7e27ddfc52d65934a229612f6aa684bf SHA-256: ad2c8ad529c032124b5368b6466bc1dc8beb41b5a754b8366c57398deeef4fef
128 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1204.002 Malicious File: Malicious File

This XLSM file contains Excel 4.0 macros, which are a known vector for malware delivery. The macros utilize dangerous functions like RUN, CALL, and HALT, indicating an intent to execute arbitrary code. The presence of hidden sheets further suggests an attempt to conceal malicious activity. The script likely downloads and executes a second-stage payload from the embedded URL.

Heuristics 5

  • Dangerous XLM formula APIs: RUN, CALL, 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.
  • Excel 4.0 macro sheet (1 sheet(s)) high 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.
  • Suspicious extracted artifact medium EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • Hidden worksheet (hidden) low OOXML_HIDDEN_SHEET
    Excel workbook contains 19 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.open
    • http://schemas.openxmlformats.org/spreadsheetml/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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.xml
34c3b4e7d4979e2ef4f2d00e4e0c5b611073239c56f086005e456842e83ad200		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 57218 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 shell/COM execution token(s).

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