Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4150ea97d46dbdb1…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:38:44 Authoring application: Microsoft Excel First seen: 2021-09-18
MD5: 5609b492e617a0fbbfb6d24f1b19386b SHA-1: a6015f36db97943b0e1949ba39de5e59cd477926 SHA-256: 4150ea97d46dbdb15bc67d4b7806263f4a4bbc78c787ebd03114e6a2a5765be4
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro-enabled workbook. Static analysis detected an Auto_Open defined name and the use of dangerous formula APIs, specifically the RUN function, within the XLM macro sheet. This indicates the macro is designed to execute arbitrary code, likely downloading and running 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) 6504 bytes
SHA-256: dfd80ff1844fa2019377451e3460066b9d3e8a166d2dc95fce004954702c3074
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 -  rMeNsm
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H177 
' 0018     22 LABEL : Cell Value, String Constant - brCkILY len=0 
' 0018     24 LABEL : Cell Value, String Constant - FWJuDjvHj len=0 
' 0018     24 LABEL : Cell Value, String Constant - ghXNrOLbx len=0 
' 0018     24 LABEL : Cell Value, String Constant - hJBETBcMu len=0 
' 0018     20 LABEL : Cell Value, String Constant - HVMmd len=0 
' 0018     26 LABEL : Cell Value, String Constant - HWOCoVbeOxd len=0 
' 0018     22 LABEL : Cell Value, String Constant - kcWTxoB len=0 
' 0018     25 LABEL : Cell Value, String Constant - klFUDTHqCs len=0 
' 0018     21 LABEL : Cell Value, String Constant - LEGTgI len=0 
' 0018     26 LABEL : Cell Value, String Constant - MnLhqjYGswr len=0 
' 0018     27 LABEL : Cell Value, String Constant - oAamldIlcGSn len=0 
' 0018     21 LABEL : Cell Value, String Constant - pyhzDD len=0 
' 0018     24 LABEL : Cell Value, String Constant - qvPrxCRTG len=0 
' 0018     20 LABEL : Cell Value, String Constant - sLaKO len=0 
' 0018     26 LABEL : Cell Value, String Constant - tcvOwrceOKq len=0 
' 0018     25 LABEL : Cell Value, String Constant - uWQtDQBnIr len=0 
' 0018     20 LABEL : Cell Value, String Constant - WQuyU len=0 
' 0018     21 LABEL : Cell Value, String Constant - XBPwAj len=0 
' 0018     23 LABEL : Cell Value, String Constant - YBlrHptG len=0 
' 0018     23 LABEL : Cell Value, String Constant - zwMpavfq 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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