Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 265566a672a701cc…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:45:04 Authoring application: Microsoft Excel First seen: 2021-07-10
MD5: 1c6309b545e3c9fe60d1e6b84c0610f0 SHA-1: bb803a3a6c79962bac2181f8303dd21ad53a830f SHA-256: 265566a672a701ccfda8f90bb02fd335a5cccfaa7d4a56fa38cf402c36466569
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 finding indicating potential for automatic execution upon opening. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary code. This points to a macro-based downloader or dropper, a common technique for delivering further malicious payloads.

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) 6662 bytes
SHA-256: 7255473d0189cb430b430f7f85215cd2c2884186fc179f5fe8fedf4ff0943409
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     20 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  NBToySSzbcg
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A161 
' 0018     25 LABEL : Cell Value, String Constant - CbBOPYDBqk len=0 
' 0018     23 LABEL : Cell Value, String Constant - cbHeedev len=0 
' 0018     23 LABEL : Cell Value, String Constant - cgCPcHuQ len=0 
' 0018     26 LABEL : Cell Value, String Constant - ckTBaPnQhjt len=0 
' 0018     24 LABEL : Cell Value, String Constant - GEpinjrgi len=0 
' 0018     27 LABEL : Cell Value, String Constant - gvxXoYWUHBFp len=0 
' 0018     20 LABEL : Cell Value, String Constant - JxRSL len=0 
' 0018     22 LABEL : Cell Value, String Constant - mCjPjPd len=0 
' 0018     22 LABEL : Cell Value, String Constant - MitvcTZ len=0 
' 0018     27 LABEL : Cell Value, String Constant - OFuXIMXjxwuw len=0 
' 0018     24 LABEL : Cell Value, String Constant - QBHLkoWIP len=0 
' 0018     24 LABEL : Cell Value, String Constant - RcRDoqIlY len=0 
' 0018     22 LABEL : Cell Value, String Constant - ThaRkXO len=0 
' 0018     22 LABEL : Cell Value, String Constant - VAvKHPL len=0 
' 0018     26 LABEL : Cell Value, String Constant - vDuTYVVTBQP len=0 
' 0018     27 LABEL : Cell Value, String Constant - vXBmKHsLIsct len=0 
' 0018     20 LABEL : Cell Value, String Constant - xFbWS len=0 
' 0018     24 LABEL : Cell Value, String Constant - YnooqkmfT len=0 
' 0018     27 LABEL : Cell Value, String Constant - ZkFVjrmDzPKP len=0 
' 0018     21 LABEL : Cell Value, String Constant - ZosMNc 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
... (truncated)

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