Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 9938ad02c98fc91a…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:38:38 Authoring application: Microsoft Excel First seen: 2021-06-13
MD5: 4e6099b43a2f65c7a3b839fead7c9edd SHA-1: 42b757a18300a107be9d7a6e95cd09e7a2a3d03b SHA-256: 9938ad02c98fc91a7155c7d15f325377145359874786c4c50a0224870a2612ae
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 defined name, which is a critical indicator of malicious activity. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary code, likely to download and run a secondary payload. The macro sheet itself is heavily obfuscated, preventing a deeper analysis of its exact function.

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) 6443 bytes
SHA-256: 96a304e8a0150915b44862dd12dd378c94651920c5aa6ef57a63856414001a15
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  Jnyhg
' 0018     20 LABEL : Cell Value, String Constant - asQJc len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!E184 
' 0018     22 LABEL : Cell Value, String Constant - bCCUALt len=0 
' 0018     25 LABEL : Cell Value, String Constant - bTuXmPHrDz len=0 
' 0018     23 LABEL : Cell Value, String Constant - cBDPpNuk len=0 
' 0018     25 LABEL : Cell Value, String Constant - DcqJYDjsDA len=0 
' 0018     20 LABEL : Cell Value, String Constant - DeMnb len=0 
' 0018     21 LABEL : Cell Value, String Constant - dnOSPV len=0 
' 0018     21 LABEL : Cell Value, String Constant - ENiTPf len=0 
' 0018     23 LABEL : Cell Value, String Constant - fnRSZrXg len=0 
' 0018     25 LABEL : Cell Value, String Constant - FonKujDAEp len=0 
' 0018     22 LABEL : Cell Value, String Constant - KBKlKXf len=0 
' 0018     24 LABEL : Cell Value, String Constant - KiBNKRtjd len=0 
' 0018     23 LABEL : Cell Value, String Constant - kvRDYJcr len=0 
' 0018     26 LABEL : Cell Value, String Constant - mdCgNDVkHKP len=0 
' 0018     27 LABEL : Cell Value, String Constant - muvwXRgWmAUn len=0 
' 0018     22 LABEL : Cell Value, String Constant - OZxqefu len=0 
' 0018     23 LABEL : Cell Value, String Constant - SwMoTajP len=0 
' 0018     26 LABEL : Cell Value, String Constant - VVWRKGtynSy len=0 
' 0018     23 LABEL : Cell Value, String Constant - ygmBcXYR len=0 
' 0018     24 LABEL : Cell Value, String Constant - YsFrBEpeD 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
' 00fd     10 LA
... (truncated)

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