Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 87751bcfa2402790…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:40:57 Authoring application: Microsoft Excel First seen: 2021-09-23
MD5: abc0e394dcb48da9772d513500c1c585 SHA-1: 26720318a11d52c7b608252e37e9de7c26056dea SHA-256: 87751bcfa2402790d0312a78c64ca15762b72eaaf88057bc4a31c1a827bc10a9
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 entry, 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 code. While the specific payload or URL is not directly visible, the structure strongly implies a downloader or initial execution stage for 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) 6589 bytes
SHA-256: ddf81d68f136d2e8bf0cac4e5334dabe22ac33867b2f1a5f90b76ce811687783
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     13 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  jwCc
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!E159 
' 0018     27 LABEL : Cell Value, String Constant - BTqJOzNAxItN len=0 
' 0018     24 LABEL : Cell Value, String Constant - DHgLlMYbD len=0 
' 0018     20 LABEL : Cell Value, String Constant - EXUSJ len=0 
' 0018     21 LABEL : Cell Value, String Constant - facsEP len=0 
' 0018     24 LABEL : Cell Value, String Constant - fMJjYPFsw len=0 
' 0018     20 LABEL : Cell Value, String Constant - FxNWD len=0 
' 0018     26 LABEL : Cell Value, String Constant - FZWQkapXbmt len=0 
' 0018     23 LABEL : Cell Value, String Constant - IajlOvZa len=0 
' 0018     24 LABEL : Cell Value, String Constant - irHOdqjby len=0 
' 0018     20 LABEL : Cell Value, String Constant - jmqxl len=0 
' 0018     24 LABEL : Cell Value, String Constant - JrNlqkMMH len=0 
' 0018     27 LABEL : Cell Value, String Constant - nCFNxOABzJuP len=0 
' 0018     20 LABEL : Cell Value, String Constant - NDhGL len=0 
' 0018     22 LABEL : Cell Value, String Constant - nxJmdfA len=0 
' 0018     23 LABEL : Cell Value, String Constant - qSxDOHfW len=0 
' 0018     20 LABEL : Cell Value, String Constant - qZHmP len=0 
' 0018     20 LABEL : Cell Value, String Constant - SyXdF len=0 
' 0018     21 LABEL : Cell Value, String Constant - ujXysI len=0 
' 0018     23 LABEL : Cell Value, String Constant - XozmPZlv len=0 
' 0018     21 LABEL : Cell Value, String Constant - yadpik 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 LABELSST : Cell Va
... (truncated)

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