IcedID Office (OOXML) / .XLSM malware analysis — malicious · 5b79b62d158feec3

MALICIOUS

Office (OOXML) / .XLSM

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

MD5: 8a28166f6fa5a200395bebff13272792 SHA-1: 8de9bd7e2bc48ce41eb511359bab6ddc3423f247 SHA-256: 5b79b62d158feec31129db57d9a766a52a7d28c476dcc716478c766d4c21d9ad

250 Risk Score

Malware Insights

IcedID · confidence 95%

MITRE ATT&CK

T1059.005 Visual Basic T1204.002 Malicious File T1105 Ingress Tool Transfer

The file contains critical heuristic firings indicating the presence of Excel 4.0 macros, including dangerous API calls like FORMULA, REGISTER, and HALT, which are used to download and execute payloads. The macros construct commands to download files named 'Hikos.hertolo', 'Hikos.hertolo1', and 'Hikos.hertolo2' using IP addresses as sources, and then execute them via 'regsvr32'. This strongly suggests a downloader functionality, consistent with the IcedID family.

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` `1be8892bef9f9957bb32d2c77ba6054081ef0bc1d79ce7bef02d37f542dbf89b`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet1.xml	3786 bytes
`xlm_sheet_01.xml` `05429996701eacd52396b49a7b542ebf5f54ec159e49392a0fde30360c280f6c`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet2.xml	2017 bytes
`xlm_sheet_02.xml` `c93414afa90d0aed96b0ce72668e15428c1af49ef990d4433b19efa6b27dd697`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet3.xml	2703 bytes
`xlm_sheet_03.xml` `caf907d21dc38a6bc75aedd846db9e62599779d4c2dbd3f24898f275d22c250a`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet4.xml	1521 bytes
`xlm_sheet_04.xml` `7667966c8045cbbf1d7c1f279245a5e7c4ac004e5ebe30fbd872010d3792710f`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet5.xml	1791 bytes
`xlm_sheet_05.xml` `c2e30072b0b55de845ae0cc0cf580b57d25538df7bd72d890703ffb59bd466f3`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet6.xml	1667 bytes
`xlm_sheet_06.xml` `4a0db02a3673bae10855faec06cd35685ff751631b0072a271b38d935beecf95`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet7.xml	1735 bytes
`xlm_sheet_07.xml` `a0c80460b9f4e41cc5c80274d1c193d030f8b4e954b0aa51ef669e0af14e35d8`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet8.xml	1679 bytes
`xlm_sheet_08.xml` `1c52474b1448a0ffd9d21d1a06b05ada2668f4c15ffc52265026119f5dff69ca`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/intlsheet9.xml	1611 bytes
`xlm_sheet_09.xml` `6dabbcd902efa205f4f62712457f79144c15a373fe7c951a3cc043bb5817e545`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet1.xml	1790 bytes

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