Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b6cd8baf0a5e44d9…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:38:24 Authoring application: Microsoft Excel First seen: 2021-07-02
MD5: 4a3855e0479e8b15d14029029a4fb60d SHA-1: 4e1701f0b1882e296278194869eb51c1b27c26d7 SHA-256: b6cd8baf0a5e44d9ab828c98c5163d76ad4a8b7c00ca50988fab15a8007e458a
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 (XLM) macros, specifically an Auto_Open defined name, which is a critical finding indicating automatic execution upon opening. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary commands. This points to a macro-based malware delivery mechanism, likely a downloader for 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) 6591 bytes
SHA-256: 10d8c2274f4289a1baf935521e8166d1c674770baf94326b359e3fbe4b5f7f01
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 -  NdYOokQ
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A175 
' 0018     20 LABEL : Cell Value, String Constant - biUtz len=0 
' 0018     25 LABEL : Cell Value, String Constant - bRBqvtFQin len=0 
' 0018     24 LABEL : Cell Value, String Constant - bXkvUGRxr len=0 
' 0018     25 LABEL : Cell Value, String Constant - HOJhIPPcIn len=0 
' 0018     24 LABEL : Cell Value, String Constant - hXwlIIsok len=0 
' 0018     24 LABEL : Cell Value, String Constant - jfDFyjbqR len=0 
' 0018     27 LABEL : Cell Value, String Constant - KeuHzlDiEEPU len=0 
' 0018     21 LABEL : Cell Value, String Constant - kwXtDn len=0 
' 0018     21 LABEL : Cell Value, String Constant - ldgKYI len=0 
' 0018     23 LABEL : Cell Value, String Constant - obdkukrM len=0 
' 0018     27 LABEL : Cell Value, String Constant - OuVVuUgKgrHC len=0 
' 0018     24 LABEL : Cell Value, String Constant - pQOTPQvhJ len=0 
' 0018     21 LABEL : Cell Value, String Constant - QPbyIY len=0 
' 0018     27 LABEL : Cell Value, String Constant - RsUxgCXsWZwX len=0 
' 0018     25 LABEL : Cell Value, String Constant - ShNwbPncpv len=0 
' 0018     20 LABEL : Cell Value, String Constant - THSsd len=0 
' 0018     23 LABEL : Cell Value, String Constant - Ufcvvjdu len=0 
' 0018     27 LABEL : Cell Value, String Constant - XdFZGMYvWNBH len=0 
' 0018     25 LABEL : Cell Value, String Constant - XEotzLpsgl len=0 
' 0018     22 LABEL : Cell Value, String Constant - xKYdaWd 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)

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