Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 8fe664204c5f6791…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-27 11:38:44 Authoring application: Microsoft Excel First seen: 2021-09-22
MD5: 2cf0150727a0c49a0c0d82675b33ea79 SHA-1: 3424002a3d992dc7ee41a3da237a9145944a39fc SHA-256: 8fe664204c5f6791149e860ff6115f42af5b9a616f3d6017929e15518f76bbac
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 sheet that contains an Auto_Open defined name, indicating it will execute automatically when the workbook is opened. Heuristics indicate the use of dangerous formula APIs, suggesting the macro is designed to execute arbitrary code. The presence of an Auto_Open entry and the use of dangerous functions strongly suggest an attempt to execute a malicious 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) 6755 bytes
SHA-256: 00a3141179b7a0964ab1f528b51328310a359f80781f63caea3a7570e110b535
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     18 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  ZCEgJoIDu
' 0018     21 LABEL : Cell Value, String Constant - ABrwak len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C173 
' 0018     23 LABEL : Cell Value, String Constant - BOhCKtWP len=0 
' 0018     20 LABEL : Cell Value, String Constant - btOKO len=0 
' 0018     22 LABEL : Cell Value, String Constant - bZNlsaM len=0 
' 0018     27 LABEL : Cell Value, String Constant - cByRKqSWKpkl len=0 
' 0018     26 LABEL : Cell Value, String Constant - CiuJCgFSvEZ len=0 
' 0018     24 LABEL : Cell Value, String Constant - DdOWTDsPl len=0 
' 0018     20 LABEL : Cell Value, String Constant - FYndG len=0 
' 0018     23 LABEL : Cell Value, String Constant - ghdeycEr len=0 
' 0018     25 LABEL : Cell Value, String Constant - JiDJCTSABg len=0 
' 0018     20 LABEL : Cell Value, String Constant - jlqCe len=0 
' 0018     27 LABEL : Cell Value, String Constant - lgnuncHrzdMN len=0 
' 0018     21 LABEL : Cell Value, String Constant - LPWilj len=0 
' 0018     22 LABEL : Cell Value, String Constant - QkysViy len=0 
' 0018     27 LABEL : Cell Value, String Constant - rZubvESCLJJe len=0 
' 0018     24 LABEL : Cell Value, String Constant - SREiEkalv len=0 
' 0018     24 LABEL : Cell Value, String Constant - URGhlNGtd len=0 
' 0018     21 LABEL : Cell Value, String Constant - YfHXgC len=0 
' 0018     23 LABEL : Cell Value, String Constant - YWeuIZPI len=0 
' 0018     23 LABEL : Cell Value, String Constant - ZogDKGis 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 
... (truncated)

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