Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 8743d6419c8a2c8c…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:40:00 Authoring application: Microsoft Excel First seen: 2021-06-17
MD5: 418d37614475a98f045a625060cdcbab SHA-1: f8a179a2fd01f7e6f35da2dc78dc4b4b82af205a SHA-256: 8743d6419c8a2c8cae0f2405c2ab487de80c4ca9d2a7f255343381b0c79bc83d
140 Risk Score

Malware Insights

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

The file is an Excel document containing Excel 4.0 (XLM) macros, specifically an Auto_Open macro. This macro is designed to execute automatically upon opening the document. The presence of dangerous formula APIs like RUN indicates that the macro is intended to execute arbitrary code, likely downloading and running a secondary 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) 6485 bytes
SHA-256: 5928bc9c1ef00209fe1856119c89b679d0e15ec5580c121caf958b4068006d9c
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  ezPtC
' 0018     27 LABEL : Cell Value, String Constant - aHvUrwwbVbQy len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B164 
' 0018     22 LABEL : Cell Value, String Constant - bjROLwB len=0 
' 0018     22 LABEL : Cell Value, String Constant - dfhPveZ len=0 
' 0018     22 LABEL : Cell Value, String Constant - eEGSOdt len=0 
' 0018     24 LABEL : Cell Value, String Constant - enRBNQUKi len=0 
' 0018     23 LABEL : Cell Value, String Constant - fUcpQKLZ len=0 
' 0018     21 LABEL : Cell Value, String Constant - GfqZam len=0 
' 0018     22 LABEL : Cell Value, String Constant - GJsLxSh len=0 
' 0018     21 LABEL : Cell Value, String Constant - ifpJjy len=0 
' 0018     23 LABEL : Cell Value, String Constant - jsDtdIqe len=0 
' 0018     25 LABEL : Cell Value, String Constant - lZWnVyzoYf len=0 
' 0018     24 LABEL : Cell Value, String Constant - nRzeubLRI len=0 
' 0018     27 LABEL : Cell Value, String Constant - nwvUOqzDCQge len=0 
' 0018     26 LABEL : Cell Value, String Constant - OFQNzVhtiAu len=0 
' 0018     25 LABEL : Cell Value, String Constant - oZUvNykVuA len=0 
' 0018     23 LABEL : Cell Value, String Constant - TBAiWXNm len=0 
' 0018     20 LABEL : Cell Value, String Constant - UEFdi len=0 
' 0018     22 LABEL : Cell Value, String Constant - ujvberE len=0 
' 0018     24 LABEL : Cell Value, String Constant - xxxABsHAP len=0 
' 0018     20 LABEL : Cell Value, String Constant - YSQtF 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 LABE
... (truncated)

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