Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3b01947a77e397b9…

MALICIOUS

Office (OLE)

37.0 KB Created: 2020-11-27 11:44:59 Authoring application: Microsoft Excel First seen: 2021-07-13
MD5: 1326958b0050c03f71dc757cdee4ea4d SHA-1: 609d2cfbbf607bd2d99cbec0bdd2d813a74a3651 SHA-256: 3b01947a77e397b92bbb34ec950e0142cc55f351788e32b8fa1d43eaaa3aa6e2
140 Risk Score

Malware Insights

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

The sample is an Excel 4.0 macro-enabled workbook. Static analysis detected the presence of an Auto_Open defined name, indicating that the macro sheet will execute automatically when the workbook is opened. The presence of dangerous formula APIs like RUN suggests the macro is intended to execute arbitrary code, likely downloading and running a second-stage payload. No specific family could be identified.

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) 6832 bytes
SHA-256: 7597c6f1aa4b64bc869297f44374586f05ec1fd28389c560a0fb260211a35594
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     16 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  LOoaGLK
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!E182 
' 0018     26 LABEL : Cell Value, String Constant - bHMgTGFzGSM len=0 
' 0018     22 LABEL : Cell Value, String Constant - FMoOswr len=0 
' 0018     22 LABEL : Cell Value, String Constant - GYNwWQb len=0 
' 0018     23 LABEL : Cell Value, String Constant - JomzcMQl len=0 
' 0018     26 LABEL : Cell Value, String Constant - KwXDcxhOMNx len=0 
' 0018     23 LABEL : Cell Value, String Constant - LVTurYjI len=0 
' 0018     20 LABEL : Cell Value, String Constant - LzLOa len=0 
' 0018     26 LABEL : Cell Value, String Constant - mJmiWRXtwcj len=0 
' 0018     23 LABEL : Cell Value, String Constant - NGRrBXuY len=0 
' 0018     27 LABEL : Cell Value, String Constant - nODddyzecvnX len=0 
' 0018     22 LABEL : Cell Value, String Constant - OanGksN len=0 
' 0018     24 LABEL : Cell Value, String Constant - OxvhFKNJA len=0 
' 0018     27 LABEL : Cell Value, String Constant - PNkToHLmaAcq len=0 
' 0018     21 LABEL : Cell Value, String Constant - qHBVUk len=0 
' 0018     22 LABEL : Cell Value, String Constant - SDuXQvz len=0 
' 0018     20 LABEL : Cell Value, String Constant - umbik len=0 
' 0018     25 LABEL : Cell Value, String Constant - uQcWaCnwle len=0 
' 0018     27 LABEL : Cell Value, String Constant - VjwrETdRxVDv len=0 
' 0018     23 LABEL : Cell Value, String Constant - VqKTnbYH len=0 
' 0018     26 LABEL : Cell Value, String Constant - XWCwKCBaMvJ 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
' 00
... (truncated)

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