Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 684d346ced32179f…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:39:54 Authoring application: Microsoft Excel First seen: 2021-10-23
MD5: b949f47a6c459fda6ba4fcb5c2abee08 SHA-1: 24f725bc1b29baf29f4466f80debf939b7cba69c SHA-256: 684d346ced32179f4e7b4c83305f9ff81c741728d87e349d645adb2c538704eb
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 containing an Auto_Open defined name, which is a common technique for executing malicious code automatically when the workbook is opened. The presence of dangerous formula APIs in the Auto_Open function further indicates malicious intent. While the specific payload is not clear from the provided evidence, the mechanism strongly suggests an attempt to execute arbitrary code.

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) 6732 bytes
SHA-256: eea7d34c52b3552f872632b357f02fa9253491c751cb439bcad1adf571abecf1
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 -  RaGkTjt
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I148 
' 0018     24 LABEL : Cell Value, String Constant - bKwkuYrqq len=0 
' 0018     20 LABEL : Cell Value, String Constant - FMxik len=0 
' 0018     26 LABEL : Cell Value, String Constant - fZVHOlxfJJF len=0 
' 0018     21 LABEL : Cell Value, String Constant - gdTQnS len=0 
' 0018     26 LABEL : Cell Value, String Constant - HnRfLCdCuyn len=0 
' 0018     23 LABEL : Cell Value, String Constant - iHVKmFZv len=0 
' 0018     21 LABEL : Cell Value, String Constant - JKoXSm len=0 
' 0018     23 LABEL : Cell Value, String Constant - MWhiRtTb len=0 
' 0018     26 LABEL : Cell Value, String Constant - nMyRyUmnxbk len=0 
' 0018     27 LABEL : Cell Value, String Constant - PASESoaRYLoy len=0 
' 0018     24 LABEL : Cell Value, String Constant - qFhFRZFrs len=0 
' 0018     21 LABEL : Cell Value, String Constant - SOMpMo len=0 
' 0018     20 LABEL : Cell Value, String Constant - TGDkk len=0 
' 0018     27 LABEL : Cell Value, String Constant - ThjpajWvGpPy len=0 
' 0018     26 LABEL : Cell Value, String Constant - uKXNAHndKki len=0 
' 0018     27 LABEL : Cell Value, String Constant - uMfwaxMBhQxI len=0 
' 0018     21 LABEL : Cell Value, String Constant - VFChea len=0 
' 0018     27 LABEL : Cell Value, String Constant - vXbtTYxCbOni len=0 
' 0018     22 LABEL : Cell Value, String Constant - YTyMWIW len=0 
' 0018     25 LABEL : Cell Value, String Constant - zgVfmdhtmC 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)

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