IcedID — Office (OOXML) / .XLSM malware analysis

Static analysis result for SHA-256 e90de33642fdd801…

MALICIOUS

Office (OOXML) / .XLSM

174.2 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300
MD5: 31e683c8b19c33c98defd4a9d5a6b11a SHA-1: 174291e69bad05843872dfca4311d556e0cb675c SHA-256: e90de33642fdd8010eddd5ea38f57ea6e97b3c46dc98766473f1eaea0591c40e
250 Risk Score

Malware Insights

IcedID · confidence 95%

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

The sample is an XLSM file containing Excel 4.0 macros, indicated by multiple critical heuristic firings. The presence of dangerous XLM formula APIs like FORMULA, GOTO, and HALT suggests the macros are designed to execute arbitrary code, likely to download and run a secondary payload. ClamAV detection confirms this as a downloader, specifically identifying it as IcedID.

Heuristics 6

  • Excel 4.0 macro sheet (6 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, GOTO, 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.
  • ClamAV: Xls.Downloader.IcedID-9f1f1d193a2a2a2b-9951463-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.IcedID-9f1f1d193a2a2a2b-9951463-0
  • Hidden worksheet (hidden) low OOXML_HIDDEN_SHEET
    Excel workbook contains 6 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://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
xlm_sheet_00.xml
e26278d9df62929caddc39c2675d1a93c805965a35896b4c4240468b728373e2
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml 1190 bytes
xlm_sheet_01.xml
b0c92abb60a2275195a7039b8d0c793da46292b6cf2282abe16347418f199576
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet2.xml 3195 bytes
xlm_sheet_02.xml
60860e3e942fc249672c3f297fa7f4b06db5f5d49d084784eafb2c3e4889ad39
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet3.xml 2298 bytes
xlm_sheet_03.xml
f6023b616a33da16850bd04bca335ab61b8bf9717cbe0a8ef91527cea67ae7fd
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet4.xml 2025 bytes
xlm_sheet_04.xml
d60ca3a864e3f818e7a00f9aa3f6fdbc180e13ef9ef26c0d3de35bf633fcfa97
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/intlsheet5.xml 1560 bytes
xlm_sheet_05.xml
dd9efeb7c324f68d06e9a7e99610df77ef935e2fc86a64fc3a473904f7bcfe45
xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 1821 bytes