Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 bcd1707aa9e4370a…

MALICIOUS

Office (OLE)

69.0 KB Created: 2006-09-13 11:21:51 Authoring application: Microsoft Excel First seen: 2020-09-24
MD5: 3afa7c20ffcec8474a20b3dbfc837efd SHA-1: d480426bd3c4feebac8ee0d646f7cecffbb62228 SHA-256: bcd1707aa9e4370aea4ba40a5f22d380ba849446e9bcc7b68b0cb4ffbaab8ee8
200 Risk Score

Malware Insights

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

The file contains Excel 4.0 (XLM) macros, specifically triggering Auto_Open and Auto_Close functions. Critical heuristics indicate the use of dangerous functions, including 'RUN', which is commonly used to execute arbitrary code. The presence of legacy macro virus markers further supports its malicious nature. The document body contains what appears to be a list of names and locations, likely a lure.

Heuristics 4

  • 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.
  • Legacy Excel formula macro virus marker critical OLE_XLS_FORMULA_MACRO_VIRUS
    Workbook stream contains self-identifying legacy Excel formula macro virus markers. This indicates the document carries formula macro virus content even when no VBA project or modern XLM macro-sheet structure is present.
  • 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) 54065 bytes
SHA-256: 7c4962f658867879ddd66999e25eef43f20706a0d7651fa8d2f81950624a9209
Preview script
First 1,000 lines of the extracted script
' 0085     16 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -   \f
' 0085     16 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, hidden -  00000pp
' 0018     31 LABEL : Cell Value, String Constant - _Fill hidden len=11 ptgAreaErr3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x00\x00m\x00m\x00m\x00m\x00'
' 0018     32 LABEL : Cell Value, String Constant - aiu_bottom len=7 ptgRefErr3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x06\x00\t\t\t\t'
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 2 Auto_Close len=7 ptgRef3d 10!C4 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d 10!C4 
' 0018     26 LABEL : Cell Value, String Constant - Bust len=7 ptgRef3d 10!C31 
' 0018     30 LABEL : Cell Value, String Constant - Continue len=7 ptgRef3d 10!C9 
' 0018     89 LABEL : Cell Value, String Constant - Document_array len=8 ptgArrayA  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x01\x00\x00\xb8\x1d\x86\x02'
' 0018     41 LABEL : Cell Value, String Constant - Documents_array len=11 ptgArea3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\n\x00\x00\x00\x0f\x00\x01\x00\x01\x00'
' 0018     25 LABEL : Cell Value, String Constant - FRC len=7 ptgRef3d 2!C9 
' 0018     27 LABEL : Cell Value, String Constant - Hello len=7 ptgRef3d 10!A15 
' 0018     29 LABEL : Cell Value, String Constant - hostfee len=7 ptgRef3d 6!H12 
' 0018     34 LABEL : Cell Value, String Constant - hraiu_bottom len=7 ptgRefErr3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x06\x00\n\n\n\n'
' 0018     26 LABEL : Cell Value, String Constant - hvac len=7 ptgRefErr3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x06\x00\x12\x12\x12\x12'
' 0018     25 LABEL : Cell Value, String Constant - HWSheet len=3 ptgInt 1 
' 0018     28 LABEL : Cell Value, String Constant - MakeIt len=7 ptgRef3d 10!A26 
' 0018     37 LABEL : Cell Value, String Constant - Module.Prix_SMC len=7 ptgNameX  NAMEIDX 16 
' 0018     29 LABEL : Cell Value, String Constant - Morning len=7 ptgRef3d 10!C39 
' 0018     28 LABEL : Cell Value, String Constant - OS len=11 ptgAreaErr3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x01\x00\x05\x80\x05\x80\x05\x80\x05\x80'
' 0018     29 LABEL : Cell Value, String Constant - PA7 len=11 ptgAreaErr3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x03\x00\xa3\x02\xa3\x02\xa3\x02\xa3\x02'
' 0018     29 LABEL : Cell Value, String Constant - PA8 len=11 ptgAreaErr3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x03\x00\xd8\x02\xd8\x02\xd8\x02\xd8\x02'
' 0018     29 LABEL : Cell Value, String Constant - PD1 len=11 ptgAreaErr3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x03\x00S\x05S\x05S\x05S\x05'
' 0018     30 LABEL : Cell Value, String Constant - PE12 len=11 ptgAreaErr3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x03\x00\xf0\t\xf0\t\xf0\t\xf0\t'
' 0018     30 LABEL : Cell Value, String Constant - PE13 len=11 ptgAreaErr3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x03\x00\x99\n\x99\n\x99\n\x99\n'
' 0018     29 LABEL : Cell Value, String Constant - PE6 len=11 ptgAreaErr3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x03\x00\x0c\t\x0c\t\x0c\t\x0c\t'
' 0018     29 LABEL : Cell Value, String Constant - PE7 len=11 ptgAreaErr3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x03\x00E\tE\tE\tE\t'
' 0018     29 LABEL : Cell Value, String Constant - PE8 len=11 ptgAreaErr3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x03\x00~\t~\t~\t~\t'
' 0018     29 LABEL : Cell Value, String Constant - PE9 len=11 ptgAreaErr3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x03\x00\xb7\t\xb7\t\xb7\t\xb7\t'
' 0018     29 LABEL : Cell Value, String Constant - PH1 len=11 ptgAreaErr3d  *INCOMPLETE FORMULA PARSING* Remaining, unparsed expression: b'\x03\x00\x19\t\x19\t\x19\t\x19\t'
' 0018     29 LABEL : Cell Va
... (truncated)