IcedID — Office (OOXML) / .XLSM malware analysis

Static analysis result for SHA-256 0fd9386f7d60fde0…

MALICIOUS

Office (OOXML) / .XLSM

170.5 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300
MD5: 02af5b7583b1d6e32488ad8af452fd24 SHA-1: a492d45e05c73633c0b5d07dffc7ca0e380c4a07 SHA-256: 0fd9386f7d60fde0a9e04351aa0fd31379e54f3344d4e2cd9ded43b7c7001448
242 Risk Score

Malware Insights

IcedID · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file is an XLSM document containing Excel 4.0 macros, as indicated by multiple critical heuristic firings. These macros utilize dangerous functions like FORMULA.FILL and EXEC to download and execute payloads from the provided URLs. The ClamAV detection explicitly names the family as IcedID, and the macros are designed to facilitate the execution of a second-stage payload.

Heuristics 5

  • Excel 4.0 macro sheet (2 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.FILL, GOTO, RETURN, 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.
  • ClamAV: Xls.Downloader.IcedID-9f1f1d193a2a2a2b-9951463-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.IcedID-9f1f1d193a2a2a2b-9951463-0
  • 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
    • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.xml
f7a7d858a289c655913c511b5f5d8782821a8118c456bccdca038cd83fd83627
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 4787 bytes
xlm_sheet_01.xml
ec666c9d225befa7b355659a9f4b1be9fc09d89a108ceccff5430c2c3d528ed9
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet2.xml 2475 bytes