Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 ac7795c7d99b8bee…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:42:27 Authoring application: Microsoft Excel First seen: 2021-06-28
MD5: c9304fc2cb928971cbaf8905c5e3cd95 SHA-1: 25f30a543f2020429395444388cf5fe5dddd0558 SHA-256: ac7795c7d99b8beee939649ffc7fb1ca151d77c1ef726f0f610d3da0fcfd842b
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 finding indicating potential malicious execution. The presence of dangerous formula APIs like RUN further supports this. The macro sheet itself contains obfuscated data, suggesting an attempt to hide its true functionality, likely to download and execute a second-stage payload.

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) 6703 bytes
SHA-256: b4c7c9a8cd952510d83979a1d18e315484733be050f2a21336d5ef259ce9b90f
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 -  wmKwE
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B138 
' 0018     27 LABEL : Cell Value, String Constant - BbsreRFzRbbD len=0 
' 0018     27 LABEL : Cell Value, String Constant - bcHNekmCWwmy len=0 
' 0018     26 LABEL : Cell Value, String Constant - CEzhHvITOIn len=0 
' 0018     24 LABEL : Cell Value, String Constant - EvJRoxnCy len=0 
' 0018     27 LABEL : Cell Value, String Constant - FchjgwedErNE len=0 
' 0018     25 LABEL : Cell Value, String Constant - GjkbeffMuK len=0 
' 0018     26 LABEL : Cell Value, String Constant - KCiBkDUWeKE len=0 
' 0018     23 LABEL : Cell Value, String Constant - KEGFpkGQ len=0 
' 0018     23 LABEL : Cell Value, String Constant - LUfLAdDI len=0 
' 0018     27 LABEL : Cell Value, String Constant - mjKYkLeeutUJ len=0 
' 0018     23 LABEL : Cell Value, String Constant - mZuXbdrL len=0 
' 0018     23 LABEL : Cell Value, String Constant - NOXZcsmX len=0 
' 0018     26 LABEL : Cell Value, String Constant - QkYaFsPmYZG len=0 
' 0018     25 LABEL : Cell Value, String Constant - SfbZrMKzmt len=0 
' 0018     26 LABEL : Cell Value, String Constant - TnbWiZZPJry len=0 
' 0018     24 LABEL : Cell Value, String Constant - utoKITfQi len=0 
' 0018     22 LABEL : Cell Value, String Constant - UxMaMaz len=0 
' 0018     21 LABEL : Cell Value, String Constant - YjInlo len=0 
' 0018     27 LABEL : Cell Value, String Constant - yVpYjDZKMILf len=0 
' 0018     27 LABEL : Cell Value, String Constant - ztmkYfRXxCLr 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, Str
... (truncated)

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