Office (OOXML) / .XLSX malware analysis — malicious · 563bfe18959a211f

MALICIOUS

Office (OOXML) / .XLSX

40.6 KB Created: 2020-05-05 12:58:46 UTC Authoring application: Microsoft Excel 16.0300

MD5: 1aa608b6fc75d0564d2dd07c098db8c1 SHA-1: 5d184a4c4d48f4632136583a1253d850849f1737 SHA-256: 563bfe18959a211fa6250cc3e503c402fbb4554bf09d068f0a897bb3c6cc0de2

128 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1204.002 Malicious File

This XLSX file contains multiple Excel 4.0 macro sheets, which are uncommon and often used for malicious purposes. The critical heuristic firing indicates the use of dangerous XLM functions like RUN and CALL, which are capable of executing arbitrary code and downloading payloads. The presence of hidden sheets further suggests an attempt to conceal malicious activity. The document body itself contains placeholder text and does not provide direct clues to the lure, but the macro execution is the primary threat.

Heuristics 5

Dangerous XLM formula APIs: RUN, CALL, 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.
Excel 4.0 macro sheet (12 sheet(s)) high 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.
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 12 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.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

Extracted artifacts 12

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`xlm_sheet_00.xml` `388de6ee82c6631534180ae78655d7cfebcf454f6a20c305fe052faf2cf707bf`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet1.xml	47703 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 2 shell/COM execution token(s).
`xlm_sheet_01.xml` `b49d075a062295598a30365407841088b5f7914230e9806aed12f6ff65c17e66`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet2.xml	40290 bytes
`xlm_sheet_02.xml` `192e878ea9c81c392b8779ec8689c0efa54fdc92516751f71b91d01ad7d1f5fb`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet3.xml	1086 bytes
`xlm_sheet_03.xml` `e393f95ba445f11802756729f6bbf26de076ab6935863f5d0ab3e36e6ef73499`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet4.xml	1086 bytes
`xlm_sheet_04.xml` `b039b69776ede2c5a005b9e805431efffd67fe13867911aa17c099b6ba3cadb2`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet5.xml	1086 bytes
`xlm_sheet_05.xml` `43ae707d9f635fb8e433b9295418e69adceb8060eeadd586d1d023cdc0ed54b7`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet6.xml	1086 bytes
`xlm_sheet_06.xml` `b2149c23afc9b8d0df9433452e29c59117a2266ec2296f255fe22cc0d0efccd7`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet7.xml	1086 bytes
`xlm_sheet_07.xml` `9ac267d85ff48fcc263fd368e855c2f5fc79b2b5aa51ac9c2899b0ea6f2c10f3`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet8.xml	1086 bytes
`xlm_sheet_08.xml` `3f8330348a1ce75c7ccd8991c891ca2ff873c6cf4bc17715eb69a1600a082719`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet9.xml	1086 bytes
`xlm_sheet_09.xml` `6a3d54510887c4d9257e6c71a4098a7c55fcfc0e52a6b4f2066758d1eda44313`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet10.xml	1086 bytes
`xlm_sheet_10.xml` `386bff73245bf754e4528ae3178470f8f517900ed98596b51824dfafeebbaeed`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet11.xml	1086 bytes
`xlm_sheet_11.xml` `3821ed39af1fcc6d1dd1c5c55dc2a9361a912599969e46a1dff5cc6d95b19660`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet12.xml	1086 bytes

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