Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 76b57780b9efea88…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:45:29 Authoring application: Microsoft Excel First seen: 2021-06-28
MD5: 585ce538f3329e9fd6d5550c8df2ec89 SHA-1: 4a65b59e48d9c9385d55a33e18085509aed618b9 SHA-256: 76b57780b9efea88a71889ef7b80531c86f86d879febb4646c00218005810b35
140 Risk Score

Malware Insights

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

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open defined name, which is a known technique for executing arbitrary code. The macro sheet contains a reference to a dangerous function, likely for command execution. The presence of an Auto_Open entry suggests the macro will execute automatically upon opening the workbook.

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) 6358 bytes
SHA-256: 17f8ed78e18bdade609c2e4843a463c1812a1b45015615b5f4fe6df3c3c504cc
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     13 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  KQZW
' 0018     21 LABEL : Cell Value, String Constant - ACucVB len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H149 
' 0018     20 LABEL : Cell Value, String Constant - ayNDW len=0 
' 0018     23 LABEL : Cell Value, String Constant - bFKdFKcI len=0 
' 0018     20 LABEL : Cell Value, String Constant - bsMsZ len=0 
' 0018     24 LABEL : Cell Value, String Constant - cbQmMWSNe len=0 
' 0018     21 LABEL : Cell Value, String Constant - Cpvqlt len=0 
' 0018     25 LABEL : Cell Value, String Constant - EjZacWcVFs len=0 
' 0018     23 LABEL : Cell Value, String Constant - FBogBtMC len=0 
' 0018     26 LABEL : Cell Value, String Constant - HjgXwSUBtfB len=0 
' 0018     24 LABEL : Cell Value, String Constant - IbJsqRwyX len=0 
' 0018     23 LABEL : Cell Value, String Constant - LDkCLNWU len=0 
' 0018     22 LABEL : Cell Value, String Constant - OPrxRON len=0 
' 0018     26 LABEL : Cell Value, String Constant - szAtzpDsnKg len=0 
' 0018     24 LABEL : Cell Value, String Constant - UdvvhewEF len=0 
' 0018     20 LABEL : Cell Value, String Constant - Ujbrv len=0 
' 0018     21 LABEL : Cell Value, String Constant - WgAKHM len=0 
' 0018     21 LABEL : Cell Value, String Constant - XkDVTK len=0 
' 0018     23 LABEL : Cell Value, String Constant - YhnrLaxK len=0 
' 0018     23 LABEL : Cell Value, String Constant - YRiIVeib len=0 
' 0018     24 LABEL : Cell Value, String Constant - ZZcAxxQBf 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 LABELSST : Cel
... (truncated)

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