Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 2f037e4386e28ce6…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:47:21 Authoring application: Microsoft Excel First seen: 2021-06-28
MD5: 929f6d10b82371bc4aff106d1c4afcbd SHA-1: 9b1229210de43d7434ce5f204e037a9aee2a8dce SHA-256: 2f037e4386e28ce65f3b321a9a633e8b28396570f1d7fd0dcd53cc0ea2456ac5
140 Risk Score

Malware Insights

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

The file contains critical heuristic firings indicating the presence of Excel 4.0 macros with an Auto_Open defined name and dangerous formula APIs, specifically the RUN function. This suggests the macro is designed to execute arbitrary commands upon opening the workbook. The macro sheet itself contains obfuscated strings and truncated data, preventing a full analysis of its payload, but the presence of Auto_Open and the RUN function strongly implies an intent to download and execute 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) 6727 bytes
SHA-256: a92e35a9392e17f5392ccff4f70a540b9fb606228cdd34bdb72c971324747b74
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 -  zLXWifQ
' 0018     21 LABEL : Cell Value, String Constant - afdEDf len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D172 
' 0018     27 LABEL : Cell Value, String Constant - cpuyxsbCDoau len=0 
' 0018     23 LABEL : Cell Value, String Constant - FVMQuidw len=0 
' 0018     23 LABEL : Cell Value, String Constant - GTPcAJrW len=0 
' 0018     23 LABEL : Cell Value, String Constant - HbxhKQsg len=0 
' 0018     22 LABEL : Cell Value, String Constant - IEIeMQp len=0 
' 0018     25 LABEL : Cell Value, String Constant - jcKDnHpKCS len=0 
' 0018     21 LABEL : Cell Value, String Constant - KarvsV len=0 
' 0018     27 LABEL : Cell Value, String Constant - LEZgZufvZdZa len=0 
' 0018     20 LABEL : Cell Value, String Constant - Lhqvh len=0 
' 0018     24 LABEL : Cell Value, String Constant - MHBKUlrkL len=0 
' 0018     26 LABEL : Cell Value, String Constant - PjLZcCtXCze len=0 
' 0018     21 LABEL : Cell Value, String Constant - RLDOOe len=0 
' 0018     24 LABEL : Cell Value, String Constant - tUwEjNwWW len=0 
' 0018     24 LABEL : Cell Value, String Constant - vmuRbeKRU len=0 
' 0018     24 LABEL : Cell Value, String Constant - VziLSXSRF len=0 
' 0018     20 LABEL : Cell Value, String Constant - WSIiU len=0 
' 0018     27 LABEL : Cell Value, String Constant - YdrbIdkOrtDB len=0 
' 0018     25 LABEL : Cell Value, String Constant - ZGvLhGUgjj len=0 
' 0018     23 LABEL : Cell Value, String Constant - zSUatYjs 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   
... (truncated)

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