Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 cf5141d00cf45b58…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:41:38 Authoring application: Microsoft Excel First seen: 2021-10-11
MD5: 8f0ed93e88388b647b5e049cc6250de0 SHA-1: ae0709c7e714a763c6a44d18e46b7c9fb28187b5 SHA-256: cf5141d00cf45b58e655c0ed2c16f659f8ed8a63f7bac7735c115ef6ba3c7ccc
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical indicator of malicious intent. The presence of dangerous formula APIs like RUN in the Auto_Open macro suggests it's designed to execute arbitrary code. Without further script content, the exact payload is unknown, but the mechanism points to client execution via macro abuse.

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) 6810 bytes
SHA-256: dbf9fbc746517e761b2ab1d04acdb682ba025f0e09ae0f9ab6adae7e106dc52f
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 -  BVfKsGMZgI
' 0018     24 LABEL : Cell Value, String Constant - APqAPpABg len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B131 
' 0018     26 LABEL : Cell Value, String Constant - ByoBxrvwlOX len=0 
' 0018     23 LABEL : Cell Value, String Constant - FDAkDrzq len=0 
' 0018     20 LABEL : Cell Value, String Constant - fonLr len=0 
' 0018     20 LABEL : Cell Value, String Constant - gCnVa len=0 
' 0018     25 LABEL : Cell Value, String Constant - gPkKGStkVa len=0 
' 0018     27 LABEL : Cell Value, String Constant - iXhVYPpORkxx len=0 
' 0018     25 LABEL : Cell Value, String Constant - JcRfHTpQwQ len=0 
' 0018     20 LABEL : Cell Value, String Constant - LQoDT len=0 
' 0018     24 LABEL : Cell Value, String Constant - LWUdDPwtw len=0 
' 0018     22 LABEL : Cell Value, String Constant - NOFJxnq len=0 
' 0018     25 LABEL : Cell Value, String Constant - osRqRXuvye len=0 
' 0018     25 LABEL : Cell Value, String Constant - PEKCuMLBnD len=0 
' 0018     20 LABEL : Cell Value, String Constant - pEnJj len=0 
' 0018     23 LABEL : Cell Value, String Constant - sATxNUzc len=0 
' 0018     21 LABEL : Cell Value, String Constant - sHfJAH len=0 
' 0018     21 LABEL : Cell Value, String Constant - sOrpOH len=0 
' 0018     26 LABEL : Cell Value, String Constant - tBysDTldiwj len=0 
' 0018     27 LABEL : Cell Value, String Constant - wVgDfgYQgVkl len=0 
' 0018     20 LABEL : Cell Value, String Constant - xzRky 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     1
... (truncated)

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