Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 fdbf707ffa4daf98…

MALICIOUS

Office (OOXML)

365.5 KB Created: 2019-01-28 15:00:04 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2021-10-16
MD5: 8953f1f50245011d0d36e27ab2b83466 SHA-1: c7bf9498645f394a85fe097df8546bae67b0f810 SHA-256: fdbf707ffa4daf986b8e956a7b7f23b2c71b603615d996222cc56a9ec1557a99
108 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The sample is an OOXML document containing VBA macros, specifically an Auto_Open macro, which is a common technique for executing malicious code upon opening. The presence of an external relationship pointing to a local file path suggests a potential attempt to trick the user into opening a related malicious file or to establish a reference for payload execution. The VBA code itself was truncated, but the Auto_Open heuristic indicates it is designed to run automatically, likely to download and execute a secondary payload.

Heuristics 4

  • External relationship high OOXML_EXTERNAL_REL
    External target in xl/externalLinks/_rels/externalLink4.xml.rels: file:///\\STA022-N2\Construction\WORKS\6787\civil\final\option\6787CWFASE2CASE2_00.xls
  • VBA project inside OOXML medium 1 related finding OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_Open macro
  • Hidden worksheet (hidden, veryHidden) low OOXML_HIDDEN_SHEET
    Excel workbook contains 3 hidden sheet(s) — hidden sheets are commonly used to conceal macro code, staging data, or intermediate payload construction

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) 11955 bytes
SHA-256: 6957eebe2bf87267d62243b46ad65f6871f09ce638b7e6db9a19462196c1a02c
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "Module1"

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 = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Trang_t¨ªnh2"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Trang_t¨ªnh4"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Sheet47"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Sheet17"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Sheet35"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Sheet2"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Module2"
Sub KTHH_HG()
Attribute KTHH_HG.VB_ProcData.VB_Invoke_Func = " \n14"
    Range("S38:V52").Select
    Selection.Copy
    Range("M38").Select
    Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
        :=False, Transpose:=False
    Application.CutCopyMode = False
    Range("Q38").Select
    ActiveSheet.Range("$B$38:$D$54").AutoFilter Field:=1, Criteria1:="<>"
End Sub
Sub CD_DAY_HG()
Attribute CD_DAY_HG.VB_ProcData.VB_Invoke_Func = " \n14"
    Range("S41:U55").Select
    Selection.Copy
    Range("K41:M41").Select
    Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
        :=False, Transpose:=False
       Application.CutCopyMode = False
    Range("R42").Select
     ActiveSheet.Range("$Q$41:$Q$56").AutoFilter Field:=1, Criteria1:="ok"
End Sub
Sub KTHH_HM_C()
Attribute KTHH_HM_C.VB_ProcData.VB_Invoke_Func = " \n14"
    Range("R42").Select
    ActiveWindow.SmallScroll Down:=27
    Range("R42:U70").Select
    Selection.Copy
    ActiveWindow.SmallScroll Down:=-21
    Range("M42").Select
    Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
        :=False, Transpose:=False
    Application.CutCopyMode = False
    Range("Q43").Select
End Sub
Sub KTHH_HM_C_HIDE()
Attribute KTHH_HM_C_HIDE.VB_ProcData.VB_Invoke_Func = " \n14"
    Range("Q42").Select
    ActiveSheet.Range("$Q$41:$Q$70").AutoFilter Field:=1, Criteria1:="ok"
End Sub
Sub CD_BTL_C()
    Range("S41:u55").Select
    Selection.Copy
    Range("M41").Select
    Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
        :=False, Transpose:=False
    Application.CutCopyMode = False
    Range("Q41").Select
    ActiveSheet.Range("$q$41:$q$55").AutoFilter Field:=1, Criteria1:="ok"
End Sub


Attribute VB_Name = "Module4"
Sub LIST()
Attribute LIST.VB_ProcData.VB_Invoke_Func = " \n14
... (truncated)
vbaProject_00.bin vba-project OOXML VBA project: xl/vbaProject.bin 56832 bytes
SHA-256: 8570fbfec30eed0a1c8ae60c1642f811e24302c0b00949fd3a68d63d22ac3532

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