IcedID Office (OOXML) / .XLSX malware analysis — malicious · 1806416f4f2b5735

MALICIOUS

Office (OOXML) / .XLSX

329.9 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300

MD5: 49079a0f50cb59f7be7daceceadc531a SHA-1: f34e6c356b0ab0f3d3df6a3cd7ef78e8fbf1088b SHA-256: 1806416f4f2b573598c5eb243a036be673e98d57e8eef9d6f050ec19e87a8728

250 Risk Score

Malware Insights

IcedID · confidence 95%

MITRE ATT&CK

T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file contains Excel 4.0 macros, identified by multiple critical heuristics, including the use of dangerous API functions like FORMULA, GOTO, REGISTER, and HALT. These macros are designed to download a payload from IP addresses such as 217.147.172.65 and execute it using rundll32. The ClamAV detection explicitly names the family as IcedID.

Heuristics 6

Excel 4.0 macro sheet (10 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, REGISTER, 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 10 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.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 10

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`xlm_sheet_00.xml` `080bf0d1913eabdbe68c9f55d92e797adb72f1bc1d886b19764eaaf321e40bcc`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml	3139 bytes
`xlm_sheet_01.xml` `05164b9cb70e0037b39b203885ebd44decd4d50bf6d78fd17a97030d1a30d169`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet2.xml	1775 bytes
`xlm_sheet_02.xml` `57964786069256c3cde5b674c74c83e32c7950a5a81fb86406607b9295962e79`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet3.xml	2200 bytes
`xlm_sheet_03.xml` `8e54ca9c8231ff6eeb2f34ba5a3783f05811c03293e81c3321c593743fc7d49b`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet4.xml	1453 bytes
`xlm_sheet_04.xml` `bc63d00a02951125a391dfed946345cbbd3e47d5e732e1f67ca4c1232e853427`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet5.xml	1453 bytes
`xlm_sheet_05.xml` `1da17f060335fdb67c88a8c48e73de301d69d9af4b69c610a8ce665eeb86cad7`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet6.xml	1452 bytes
`xlm_sheet_06.xml` `f6b4423280cd454553d841491284df3eff350a07bc739b9add3542ffb6a9432a`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet7.xml	1454 bytes
`xlm_sheet_07.xml` `bdf4c4c111e091debcc20b38007edacf914de0a9b4c13576faa0148f2eae61a7`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet8.xml	1455 bytes
`xlm_sheet_08.xml` `a6ea880b09fb36b15b9b86dc98d863447933c1968cf6c7d3bec7927472189efa`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet9.xml	1451 bytes
`xlm_sheet_09.xml` `6b415b149f32e6deb26c4b2856c7977501b27603cf485b4daf15fd4fee7940d5`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet1.xml	1496 bytes

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