Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 016d062791777aa3…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:45:00 Authoring application: Microsoft Excel First seen: 2020-12-28
MD5: 5d2a9991b155aa9ee862d8c07e79adad SHA-1: afa4cef696d1163b0846f9004b79b06040b26b79 SHA-256: 016d062791777aa3e8cc8d11259f7dc66421ce6f977cf5084f6f9db73a5eb1ba
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open function, which is a known technique for executing malicious code upon opening the workbook. The critical heuristic firings indicate the presence of dangerous formula APIs within the XLM macro, suggesting an attempt to run arbitrary commands or download further payloads. No specific IOCs like URLs or hashes were extracted, but the technique itself is highly suspicious.

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) 6758 bytes
SHA-256: 26521292e78745d38429fde90bcdcf4a00fcf7bd5c2da98cef02776a7384314a
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     15 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  IMXkqb
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F190 
' 0018     21 LABEL : Cell Value, String Constant - BuKhOo len=0 
' 0018     20 LABEL : Cell Value, String Constant - CbqQy len=0 
' 0018     26 LABEL : Cell Value, String Constant - dUlvXdXHoLX len=0 
' 0018     27 LABEL : Cell Value, String Constant - ECQGPaGVRVjA len=0 
' 0018     24 LABEL : Cell Value, String Constant - EpyoMFsIF len=0 
' 0018     25 LABEL : Cell Value, String Constant - FeQFywxoLD len=0 
' 0018     23 LABEL : Cell Value, String Constant - FhuXntSQ len=0 
' 0018     22 LABEL : Cell Value, String Constant - GgSiVqR len=0 
' 0018     27 LABEL : Cell Value, String Constant - GsEDXWEKpBMC len=0 
' 0018     25 LABEL : Cell Value, String Constant - jUvEvMExVV len=0 
' 0018     21 LABEL : Cell Value, String Constant - mCAKLP len=0 
' 0018     23 LABEL : Cell Value, String Constant - nADRZaVA len=0 
' 0018     24 LABEL : Cell Value, String Constant - pBjVmPrfm len=0 
' 0018     27 LABEL : Cell Value, String Constant - PWmGishDuPAv len=0 
' 0018     26 LABEL : Cell Value, String Constant - qIQmkTSfkuh len=0 
' 0018     21 LABEL : Cell Value, String Constant - UlcBVP len=0 
' 0018     21 LABEL : Cell Value, String Constant - wFDcrQ len=0 
' 0018     26 LABEL : Cell Value, String Constant - yJrjrbCAnXx len=0 
' 0018     24 LABEL : Cell Value, String Constant - zIEVenNyX len=0 
' 0018     24 LABEL : Cell Value, String Constant - zjOwcvvrJ len=0 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 0
... (truncated)

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