Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c596779c40db3275…

MALICIOUS

Office (OLE)

118.5 KB Created: 2015-03-16 02:45:00 Authoring application: Microsoft Excel First seen: 2020-08-10
MD5: b6cf23cc4a57ba3721d6f91a24bd9939 SHA-1: 7a89923753f75b721ef5a92d990c8708982878d0 SHA-256: c596779c40db3275f019af3ff3152002f6cb3b02fcca5d2bfc7e26ab94aae8d5
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The sample is an Excel file containing Excel 4.0 macros, specifically an Auto_Open macro. This macro is designed to execute automatically when the workbook is opened, and the presence of dangerous formula APIs indicates malicious intent. The document body's "DOCUMENT PROTECTED!" message is a common lure to trick users into enabling macros, which would then execute the malicious XLM code.

Heuristics 3

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 57951 bytes
SHA-256: 40442eaa48d44912f6178dfeb345e5af2c2767a7f1d4aa295fb28ce32408a4f2
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     26 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  WRQyIMLR1dK6kS8qq
' 0018     21 LABEL : Cell Value, String Constant - AGyxHH len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open hidden len=7 ptgRef3d  Sheet!BE54903 
' 0018     21 LABEL : Cell Value, String Constant - BFGWNM len=0 
' 0018     21 LABEL : Cell Value, String Constant - bKVYRG len=0 
' 0018     20 LABEL : Cell Value, String Constant - bzLRN len=0 
' 0018     19 LABEL : Cell Value, String Constant - cYQr len=0 
' 0018     19 LABEL : Cell Value, String Constant - dMwD len=0 
' 0018     18 LABEL : Cell Value, String Constant - DMY len=0 
' 0018     21 LABEL : Cell Value, String Constant - dvDwFm len=0 
' 0018     21 LABEL : Cell Value, String Constant - dvjhFg len=0 
' 0018     20 LABEL : Cell Value, String Constant - DVMTm len=0 
' 0018     19 LABEL : Cell Value, String Constant - DZOZ len=0 
' 0018     21 LABEL : Cell Value, String Constant - eEuOOh len=0 
' 0018     21 LABEL : Cell Value, String Constant - eFkIHm len=0 
' 0018     18 LABEL : Cell Value, String Constant - eNQ len=0 
' 0018     21 LABEL : Cell Value, String Constant - EOmwfJ len=0 
' 0018     34 LABEL : Cell Value, String Constant -          hidden len=11 ptgArea3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x00\x00D\x8ec\x8e\xe4\x00\xe4\x00'
' 0018     18 LABEL : Cell Value, String Constant - EZM len=0 
' 0018     18 LABEL : Cell Value, String Constant - ezY len=0 
' 0018     18 LABEL : Cell Value, String Constant - FJD len=0 
' 0018     18 LABEL : Cell Value, String Constant - FLy len=0 
' 0018     18 LABEL : Cell Value, String Constant - FsP len=0 
' 0018     19 LABEL : Cell Value, String Constant - fwnh len=0 
' 0018     21 LABEL : Cell Value, String Constant - GYKivH len=0 
' 0018     27 LABEL : Cell Value, String Constant - HFlxK hidden len=7 ptgRef3d  Sheet!BE54903 
' 0018     19 LABEL : Cell Value, String Constant - HuAm len=0 
' 0018     18 LABEL : Cell Value, String Constant - Ifl len=0 
' 0018     19 LABEL : Cell Value, String Constant - IozF len=0 
' 0018     18 LABEL : Cell Value, String Constant - iQC len=0 
' 0018     20 LABEL : Cell Value, String Constant - Irarj len=0 
' 0018     19 LABEL : Cell Value, String Constant - ISIF len=0 
' 0018     21 LABEL : Cell Value, String Constant - IZhQYq len=0 
' 0018     20 LABEL : Cell Value, String Constant - JihUb len=0 
' 0018     36 LABEL : Cell Value, String Constant -            hidden len=11 ptgArea3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x00\x00\xa1r\xc1rg\x00g\x00'
' 0018     21 LABEL : Cell Value, String Constant - jxLSdK len=0 
' 0018     18 LABEL : Cell Value, String Constant - KlL len=0 
' 0018     20 LABEL : Cell Value, String Constant - kpzpt len=0 
' 0018     21 LABEL : Cell Value, String Constant - KtQNul len=0 
' 0018     21 LABEL : Cell Value, String Constant - ktvuds len=0 
' 0018     20 LABEL : Cell Value, String Constant - LFdhd len=0 
' 0018     18 LABEL : Cell Value, String Constant - lGz len=0 
' 0018     36 LABEL : Cell Value, String Constant -            hidden len=11 ptgArea3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x00\x00ay\xb1y\x91\x00\x91\x00'
' 0018     21 LABEL : Cell Value, String Constant - MJKtrB len=0 
' 0018     19 LABEL : Cell Value, String Constant - mKBC len=0 
' 0018     21 LABEL : Cell Value, String Constant - MqVLPd len=0 
' 0018     18 LABEL : Cell Value, String Constant - MsK len=0 
' 0018     19 LABEL : Cell Value, String Constant - NpWB len=0 
' 0018     20 LABEL : Cell Value, String Constant - NXqPo len=0 
' 0018     18 LABEL : Cell Value, String Constant - oOm len=0 
' 0018     19 LABEL : Cell Value, String Constant - PjGY len=0 
' 0018     18 LABEL : Cell Value, String Constant - ptE len=0 
' 0018     21 LABEL : Cell Value, String Constant - PWRYtV len=0 
' 0018     18 LABEL : Cell Value, String Constant - qEA len=0 
' 0018     21 LABEL : Cell Value, String Constan
... (truncated)

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