Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 1c23899486b57eaa…

MALICIOUS

Office (OOXML)

180.2 KB Created: 2015-06-05 18:19:34 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2021-06-20
MD5: 95ed3a496288e2230ae05c78071f5238 SHA-1: 8e0dd34028935e720055e2dd811be3bb2338928d SHA-256: 1c23899486b57eaaeaee67a41a85e86c9b1de7bf6935e7ff95ecce8f019f6c11
190 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, indicated by critical heuristics for XLM macrosheets and dangerous function usage. The macros utilize the FORMULA API to call external functions, likely to download and execute a payload from the URLs: https://norsecompassgroup.com/4EQmRlzmq9R/lipa.html and https://corazonarquitectura.com/94REej6f3mR/lipa.html. The presence of a hidden sheet further suggests an attempt to conceal malicious activity.

Heuristics 5

  • Excel 4.0 macro sheet (1 sheet(s)) critical 2 related findings 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, 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.
  • Hidden worksheet (hidden) low OOXML_HIDDEN_SHEET
    Excel workbook contains 1 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 https://norsecompassgroup.com/4EQmRlzmq9R/lipa.html In document text (OOXML body / shared strings)
    • https://corazonarquitectura.com/94REej6f3mR/lipa.htmlIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/spreadsheetml/2006/mainIn 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/intlsheet1.xml 208638 bytes
SHA-256: 83fcfe9d8e9639d9b626df722e07fb16b44d0ebbb7dc3a56d672f68b8540615b
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="{00000000-0001-0000-0100-000000000000}"><dimension ref="A1:BV283"/><sheetViews><sheetView showFormulas="1" zoomScaleNormal="100" workbookViewId="0"/></sheetViews><sheetFormatPr defaultColWidth="4.5703125" defaultRowHeight="15" x14ac:dyDescent="0.25"/><cols><col min="1" max="39" width="4.5703125" style="2"/><col min="40" max="40" width="4.5703125" style="2" customWidth="1"/><col min="41" max="50" width="4.5703125" style="2" hidden="1" customWidth="1"/><col min="51" max="51" width="2.7109375" style="2" hidden="1" customWidth="1"/><col min="52" max="16384" width="4.5703125" style="2"/></cols><sheetData><row r="1" spans="1:41" x14ac:dyDescent="0.25"><c r="A1" s="1"/><c r="B1" s="1"/><c r="C1" s="1"/><c r="D1" s="1"/><c r="E1" s="1"/><c r="F1" s="1"/><c r="G1" s="1"/><c r="H1" s="1"/><c r="I1" s="1"/><c r="J1" s="1"/><c r="K1" s="1"/><c r="L1" s="1"/><c r="M1" s="1"/><c r="N1" s="1"/><c r="O1" s="1"/><c r="P1" s="1"/><c r="Q1" s="1"/><c r="R1" s="1"/><c r="S1" s="1"/><c r="T1" s="1"/><c r="U1" s="1"/><c r="V1" s="1"/><c r="W1" s="1"/><c r="X1" s="1"/><c r="Y1" s="1"/><c r="Z1" s="1"/><c r="AA1" s="1"/><c r="AB1" s="1"/><c r="AC1" s="1"/><c r="AD1" s="1"/><c r="AE1" s="1"/><c r="AF1" s="1"/><c r="AG1" s="1"/><c r="AH1" s="1"/><c r="AI1" s="1"/><c r="AJ1" s="1"/></row><row r="2" spans="1:41" x14ac:dyDescent="0.25"><c r="A2" s="1"/><c r="B2" s="1"/><c r="C2" s="1"/><c r="D2" s="1"/><c r="E2" s="1"/><c r="F2" s="1"/><c r="G2" s="1"/><c r="H2" s="1"/><c r="I2" s="1"/><c r="J2" s="1"/><c r="K2" s="1"/><c r="L2" s="1"/><c r="M2" s="1"/><c r="N2" s="1"/><c r="O2" s="1"/><c r="P2" s="1"/><c r="Q2" s="1"/><c r="R2" s="1"/><c r="S2" s="1"/><c r="T2" s="1"/><c r="U2" s="1"/><c r="V2" s="1"/><c r="W2" s="1"/><c r="X2" s="1"/><c r="Y2" s="1"/><c r="Z2" s="1"/><c r="AA2" s="1"/><c r="AB2" s="1"/><c r="AC2" s="1"/><c r="AD2" s="1"/><c r="AE2" s="1"/><c r="AF2" s="1"/><c r="AG2" s="1"/><c r="AH2" s="1"/><c r="AI2" s="1"/><c r="AJ2" s="1"/></row><row r="3" spans="1:41" x14ac:dyDescent="0.25"><c r="A3" s="1"/><c r="B3" s="1"/><c r="C3" s="1"/><c r="D3" s="1"/><c r="E3" s="1"/><c r="F3" s="1"/><c r="G3" s="1"/><c r="H3" s="1"/><c r="I3" s="1"/><c r="J3" s="1"/><c r="K3" s="1"/><c r="L3" s="1"/><c r="M3" s="1"/><c r="N3" s="1"/><c r="O3" s="1"/><c r="P3" s="1"/><c r="Q3" s="1"/><c r="R3" s="1"/><c r="S3" s="1"/><c r="T3" s="1"/><c r="U3" s="1"/><c r="V3" s="1"/><c r="W3" s="1"/><c r="X3" s="1"/><c r="Y3" s="1"/><c r="Z3" s="1"/><c r="AA3" s="1"/><c r="AB3" s="1"/><c r="AC3" s="1"/><c r="AD3" s="1"/><c r="AE3" s="1"/><c r="AF3" s="1"/><c r="AG3" s="1"/></row><row r="4" spans="1:41" x14ac:dyDescent="0.25"><c r="A4" s="1"/><c r="B4" s="1"/><c r="C4" s="1"/><c r="D4" s="1"/><c r="E4" s="1"/><c r="F4" s="1"/><c r="G4" s="1"/><c r="H4" s="1"/><c r="I4" s="1"/><c r="J4" s="1"/><c r="K4" s="1"/><c r="L4" s="1"/><c r="M4" s="1"/><c r="N4" s="1"/><c r="O4" s="1"/><c r="P4" s="1"/><c r="Q4" s="1"/><c r="R4" s="1"/><c r="S4" s="1"/><c r="T4" s="1"/><c r="U4" s="1"/><c r="V4" s="1"/><c r="W4" s="1"/><c r="X4" s="1"/><c r="Y4" s="1"/><c r="Z4" s="1"/><c r="AA4" s="1"/><c r="AB4" s="1"/><c r="AC4" s="1"/><c r="AD4" s="1"/><c r="AE4" s="1"/><c r="AF4" s="1"/><c r="AG4" s="1"/></row><row r="5" spans="1:41" x14ac:dyDescent="0.25"><c r="A5" s="1"/><c r="B5" s="1"/><c r="C5" s="1"/><c r="D5" s="1"/><c r="E
... (truncated)