Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 8ab4fee2609efdb1…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:46:30 Authoring application: Microsoft Excel First seen: 2021-06-28
MD5: cd9892117da8b820f0db2687ef3c2084 SHA-1: 82e1d5b94d49f50bf2d4103d1390bb03cfe1c0e3 SHA-256: 8ab4fee2609efdb11bfcdd702fe67a88e02d3b8753b68ee6f2fded9ffabe1850
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, specifically an Auto_Open defined name. Heuristics indicate the use of dangerous formula APIs within the macro, suggesting an attempt to execute arbitrary code. The presence of XLM macros and the Auto_Open entry strongly point towards an attack pattern designed to run malicious code upon opening the document.

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) 6887 bytes
SHA-256: 7b60c59a13327c018fb1bb5de03314361fc643b962c81da07e5c475ee0d3f824
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     17 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  SDUjysxg
' 0018     25 LABEL : Cell Value, String Constant - AQoXTiuoES len=0 
' 0018     21 LABEL : Cell Value, String Constant - aSByRm len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I140 
' 0018     23 LABEL : Cell Value, String Constant - CtdXEKTZ len=0 
' 0018     23 LABEL : Cell Value, String Constant - dtqbItaV len=0 
' 0018     26 LABEL : Cell Value, String Constant - eKhUbeONwux len=0 
' 0018     23 LABEL : Cell Value, String Constant - fYmdMUfJ len=0 
' 0018     24 LABEL : Cell Value, String Constant - hGrFePGkC len=0 
' 0018     20 LABEL : Cell Value, String Constant - htvJV len=0 
' 0018     26 LABEL : Cell Value, String Constant - jgDoNPPWUUj len=0 
' 0018     27 LABEL : Cell Value, String Constant - JlfzVjZWsAXC len=0 
' 0018     26 LABEL : Cell Value, String Constant - lUDoQCznSLZ len=0 
' 0018     21 LABEL : Cell Value, String Constant - nbhjsy len=0 
' 0018     27 LABEL : Cell Value, String Constant - oUgsJVPrxEtU len=0 
' 0018     27 LABEL : Cell Value, String Constant - pKiAhWvyFvKp len=0 
' 0018     24 LABEL : Cell Value, String Constant - QKHFXBChF len=0 
' 0018     24 LABEL : Cell Value, String Constant - RvbaNEpiU len=0 
' 0018     21 LABEL : Cell Value, String Constant - vCpMiX len=0 
' 0018     26 LABEL : Cell Value, String Constant - vdOwClKkAiw len=0 
' 0018     23 LABEL : Cell Value, String Constant - vJkFSaKE len=0 
' 0018     24 LABEL : Cell Value, String Constant - ZgjhlYBWr 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/ S
... (truncated)