Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 682512ba8567f588…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:38:41 Authoring application: Microsoft Excel First seen: 2021-09-22
MD5: a3615da4e38e143406980114601d7aee SHA-1: d5cc26eb4250a36cb95594ec71dc2a890b8e5860 SHA-256: 682512ba8567f5882bf4c3e406e4ec604e2e79b5c48d668a7defa29fd0105e94
140 Risk Score

Malware Insights

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

The file is an Excel document containing Excel 4.0 (XLM) macros. The presence of an 'Auto_Open' defined name indicates that the macro will execute automatically when the workbook is opened. This is a common technique for malware to download and execute a second-stage payload. The specific formulas used are not fully detailed, but the critical heuristic firings suggest the use of dangerous functions like RUN.

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) 6648 bytes
SHA-256: 15dacb27278032fe42c8545d8684e5e933cd7c69d3ccd31fe156fc780f7f9e0c
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     19 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  TKqznaqKfM
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D142 
' 0018     26 LABEL : Cell Value, String Constant - cNoHoWNguwz len=0 
' 0018     23 LABEL : Cell Value, String Constant - HCnPKqMl len=0 
' 0018     24 LABEL : Cell Value, String Constant - iODwlXpXI len=0 
' 0018     26 LABEL : Cell Value, String Constant - KElVwefXHzl len=0 
' 0018     27 LABEL : Cell Value, String Constant - kjiFMXhlCbnF len=0 
' 0018     22 LABEL : Cell Value, String Constant - KUWaDWE len=0 
' 0018     26 LABEL : Cell Value, String Constant - KZkUfcdjkXB len=0 
' 0018     21 LABEL : Cell Value, String Constant - lbkJNv len=0 
' 0018     22 LABEL : Cell Value, String Constant - LrPJrMf len=0 
' 0018     24 LABEL : Cell Value, String Constant - PakkqVAkR len=0 
' 0018     21 LABEL : Cell Value, String Constant - pwujiA len=0 
' 0018     26 LABEL : Cell Value, String Constant - QCqWoRqytFY len=0 
' 0018     26 LABEL : Cell Value, String Constant - RmKnyeINGwU len=0 
' 0018     20 LABEL : Cell Value, String Constant - ROlea len=0 
' 0018     26 LABEL : Cell Value, String Constant - VuRgEPENxfv len=0 
' 0018     25 LABEL : Cell Value, String Constant - wYXqHFpQPL len=0 
' 0018     27 LABEL : Cell Value, String Constant - xhxVHbyswZCv len=0 
' 0018     27 LABEL : Cell Value, String Constant - XyOJzmKbxwgE len=0 
' 0018     27 LABEL : Cell Value, String Constant - YALJOXbFTfbm len=0 
' 0018     22 LABEL : Cell Value, String Constant - ZTnoDLX 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 Co
... (truncated)

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