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

Static analysis result for SHA-256 5f27fe60d9f8848f…

MALICIOUS

Office (OOXML) / .XLSM

135.0 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300
MD5: 253f51190b3ad49468ce137c6685eda2 SHA-1: 536718bf10c4542734a14e657e8d90237eb6ffd9 SHA-256: 5f27fe60d9f8848f3dd4c66a4ee9144a15ce7e728f6aafc2cf7b31f8c5e4f646
270 Risk Score

Malware Insights

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

The sample is an Excel macro-enabled spreadsheet (XLSM) containing Excel 4.0 macros. These macros utilize dangerous functions like FORMULA and REGISTER, and contain strings for URLDownloadToFileA, indicating an intent to download and execute a payload. The embedded URLs are the primary indicators of compromise for the second-stage payload.

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.
  • 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: FORMULA, REGISTER, GOTO, EXEC, 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.
  • Binary XLM macro sheet with WinAPI/download strings critical OOXML_XLM_BINARY_WINAPI_STRINGS
    Excel 4.0 macro sheet is stored as BIFF12/XLSB binary data and contains Win32 download or process-execution API strings such as URLDownloadToFileA, ShellExecuteA, or CreateDirectoryA. These strings are high-signal in XLM macro sheets and catch payload-download macros that XML-formula scanners cannot parse.
  • 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 4 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://195.123.208.151/44285,5327891204.dat
    • http://188.127.227.146/44285,5327891204.dat
    • http://74.119.193.206/44285,5327891204.dat
    • http://195.123.208.151/
    • http://188.127.227.146/
    • http://74.119.193.206/
    • 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
    • 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/spreadsheetml/2016/revision6

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.xml
b5a43df94d2f97db023b19249ba79bdd1b53d1d9b7d1be89d45d77e3dcdc0d6b		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 3911 bytes
xlm_sheet_01.xml
0968b576406b659c600cdff11889e4d244b800464c83754b17dd997ba50016cb		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.xml 2166 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 shell/COM execution token(s).
xlm_sheet_02.xml
30a708989faa7ba10801984270d978a1513a80987b8b046b3d37be78bed5e5b8		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet3.xml 2080 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 shell/COM execution token(s).
xlm_sheet_03.xml
1c0bd40302a873a5eb674957d440761136078e201cfafd988e6c47500f34fe51		 xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet4.xml 2011 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 shell/COM execution token(s).

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