Office (OOXML) / .XLSX malware analysis — malicious · 87fb1682a7821751

MALICIOUS

Office (OOXML) / .XLSX

40.0 KB Created: 2020-04-29 13:43:05 UTC Authoring application: Microsoft Excel 16.0300

MD5: 7be5e0d09d430937b718616e0a844101 SHA-1: 7353d1deab83be7decc96c0bb95987337908cd99 SHA-256: 87fb1682a78217518d0eb92bfa468be345ddf3a4b00c131310dc96af72233d89

128 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1059.001 PowerShell T1204.002 Malicious File

This XLSX file contains 25 Excel 4.0 (XLM) macro sheets, which is highly suspicious as XLM is rarely used in legitimate documents. The macros utilize dangerous XLM formula APIs such as RUN and CALL, which are known primitives for executing arbitrary code. These functions are likely used to download and execute a second-stage payload, although no specific URLs or executable names were extracted from this sample. The presence of hidden sheets further supports the concealment of malicious activity.

Heuristics 5

Dangerous XLM formula APIs: RUN, CALL, HALT, FORMULA 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 (25 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 25 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 25

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`xlm_sheet_00.xml` `d286de097658367aefac32ee6fe426b03b50af356f8b56094aaed39be307edbd`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet1.xml	61161 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 2 shell/COM execution token(s).
`xlm_sheet_01.xml` `d413cc4dc472cdfba22ce81ce74994a926b4f01719e3f4e61850cdad519e7f41`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet2.xml	15792 bytes
`xlm_sheet_02.xml` `74856e04ed1da4c784dd82d9a39e659841d3d81fa25301e2bfc5422f16945d6f`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet3.xml	1086 bytes
`xlm_sheet_03.xml` `47ada420e5a2206bc639303a41a69fc501970917d5c71e6f778898bf109f172c`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet4.xml	1086 bytes
`xlm_sheet_04.xml` `275afaec655c20eb20c544e719ff827d748613576f1834161e8c6849915dd6b2`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet5.xml	1086 bytes
`xlm_sheet_05.xml` `653b72b5d52f293bfe4c8b4d9a8a2623273db09d9e522d4ca1e3a7ae3d1186a4`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet6.xml	1086 bytes
`xlm_sheet_06.xml` `1cacf57f2c0ce3f9c39ebeea8811562fc11974c708c9d7915bee1fd2991e216f`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet7.xml	1086 bytes
`xlm_sheet_07.xml` `818b1cda8c3c899e1aeb1fb3133fe01c9e40b8b1c215858d9a192a34aaa3e4fa`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet8.xml	1086 bytes
`xlm_sheet_08.xml` `f6cd6999a84fe1b540cbf1e82d6d260b9a9bcd8fe2613234b7c9771c0b012175`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet9.xml	1086 bytes
`xlm_sheet_09.xml` `3ea72f8b796e1b3d472a770873cb3bc8f5ee395be21601069484cb4c48b36e6f`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet10.xml	1086 bytes
`xlm_sheet_10.xml` `00cb5d3f13de3eaa2f4b3e05b07540e06a754f7ca82f2d70c90b3d22b142bf80`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet11.xml	1086 bytes
`xlm_sheet_11.xml` `7730c273010d7aa212a692267a1a9f37357dbfc7a40cc183d8637b864625d440`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet12.xml	1086 bytes
`xlm_sheet_12.xml` `848f383395a13ffcdf781e1376934e2d1c08a8847666840d8fe221f5aacae009`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet13.xml	1086 bytes
`xlm_sheet_13.xml` `fb56b556f17617be109ae33dbfb4853058b53f241062a4c82aa35209abe09fa6`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet14.xml	1086 bytes
`xlm_sheet_14.xml` `80d1764e1119d6f1005b785dc4ad6fda31d2942958aa2163dd80cfc0694207c2`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet15.xml	1086 bytes
`xlm_sheet_15.xml` `9b7945141124c7aacc0dc06a92e52c1674f75eea9209e06c62436866f9ea39f0`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet19.xml	1086 bytes
`xlm_sheet_16.xml` `ae2897e79cfbfe64930dc9d38030bc6b51986f18022b65010ca96d76d5ecc263`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet20.xml	1086 bytes
`xlm_sheet_17.xml` `e586ca9f3f7eec535677ee170f59d10aaac5b6532db288d991c935c9f13362ab`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet21.xml	1086 bytes
`xlm_sheet_18.xml` `83a71169cc08957c03e6844c4d5d5f8384becb230537f91dcf54d8aa9e92ed63`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet22.xml	1086 bytes
`xlm_sheet_19.xml` `1636a138a2c897e62fcb2bf440afca2aaeef79d39f834573a3c2bf40da3e35c9`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet23.xml	1086 bytes
`xlm_sheet_20.xml` `ba0c0feecbd00fc762f77b34ca7e7652bd800432cb3e4b4621b374f9d430e856`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet24.xml	1086 bytes
`xlm_sheet_21.xml` `a89b05bc62a218a2b22583d7bca473773cd771c847d8b2d9e75a664ca44beb5e`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet25.xml	1086 bytes
`xlm_sheet_22.xml` `d606ebb8d7bde419d30c660fb1ac665bbe7704d02354d5d4b64ec17f0e4de8c5`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet16.xml	1086 bytes
`xlm_sheet_23.xml` `9c59b72d602291faa1459273644f3753cd16b5c59b9de2e993eb28170e630fbe`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet18.xml	1086 bytes
`xlm_sheet_24.xml` `b732fdf1440de0919238eed0278966752efab8d738635789bafa2c3f5260b800`	xlm-macrosheet	OOXML XLM macro sheet: xl/macrosheets/sheet17.xml	1086 bytes

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