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

Static analysis result for SHA-256 be35d1add8e7e287…

MALICIOUS

Office (OOXML) / .XLSM

221.1 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300
MD5: ef01e0b77efcc06cc2465a084c1f207f SHA-1: 186b3ee6568a207668b6470c049f7fbe9c631e2a SHA-256: be35d1add8e7e2873d921f9817ceec9bd559f29e3b23c7418c496ab9e6061a75
210 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1059.001 PowerShell T1204.002 Malicious File T1105 Ingress Tool Transfer

The sample is an XLSM file containing Excel 4.0 macros, which are known to be used for malicious purposes. The critical heuristic 'OOXML_XLM_DANGEROUS_FN' indicates the use of dangerous XLM functions like FORMULA and EXEC, which are capable of downloading and executing payloads. The presence of multiple suspicious URLs further supports this, suggesting a downloader or droppper functionality.

Heuristics 7

  • Excel 4.0 macro sheet (4 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: FORMULA, GOTO, HALT, REGISTER, EXEC 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.
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_Open macro
  • VBA project inside OOXML medium OOXML_VBA
    Document contains vbaProject.bin — VBA macros present
  • 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 5 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 — context-specific rules above attribute URLs they actually evaluated; this rule lists URLs that were present in the bytes but were not otherwise tied to a specific finding.
    URL http://185.212.129.18/
    • http://195.123.247.118/
    • http://45.67.230.236/
    • http://185.212.129.18/44300,5396033565.dat
    • http://195.123.247.118/44300,5396033565.dat
    • http://45.67.230.236/44300,5396033565.dat
    • 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
    • http://schemas.microsoft.com/office/excel/2006/main
    • http://schemas.microsoft.com/office/spreadsheetml/2016/revision6

Extracted artifacts 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
727c03935089a4af8a7c689ceaec747458b5c93ac793034b8a2806c0ad0819d9		 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 807 bytes
vbaProject_00.bin
38688ee61c0fe106f773704435df469ad9b0c1a282794066efa00b4f6a615aa8		 vba-project OOXML VBA project: xl/vbaProject.bin 10240 bytes
xlm_sheet_00.xml
6f54336f92cff3197847ef078c81f1930e1a9f0cf0d9e2688775bab79ce58178		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 4432 bytes
xlm_sheet_01.xml
46dfcca5d1fa48883104077e460e6841fdec76bf2057e52d000523b9b405b463		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.xml 2629 bytes
xlm_sheet_02.xml
ffdf6d175a29832486918c4b6972ec4ec836bbf7df8929bd66cac29a460620a4		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet3.xml 2054 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 shell/COM execution token(s).
xlm_sheet_03.xml
568ef423a3db3ba99e6bb80da926ad5296860ef3b1727f2e9f0b56194a76db66		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet4.xml 1503 bytes

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