Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 79dd69d7077b9b23…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:46:51 Authoring application: Microsoft Excel First seen: 2021-07-07
MD5: cf3993341b3cda9949f177cf73ae2c92 SHA-1: 77c98eb9fec171696b142064fa3637ccd64e537b SHA-256: 79dd69d7077b9b235c079eaa76f5aba91b31d84da4b84070a72c19207653dcc1
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-enabled workbook containing an Auto_Open function. This function is designed to execute arbitrary code upon opening, leveraging dangerous formula APIs. The presence of an Auto_Open entry in an XLM macro sheet indicates a malicious intent to run code automatically, likely to download and execute 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) 6713 bytes
SHA-256: 1b04bd323c7e5d389cad8f382c5416709cbb65eec611b885d1470e2a1790d19e
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 -  AjHC
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B132 
' 0018     22 LABEL : Cell Value, String Constant - cToRyyF len=0 
' 0018     27 LABEL : Cell Value, String Constant - DfvgPyvNUPkE len=0 
' 0018     25 LABEL : Cell Value, String Constant - fkRcYWcHOi len=0 
' 0018     23 LABEL : Cell Value, String Constant - GdveKnsb len=0 
' 0018     27 LABEL : Cell Value, String Constant - gtHtUjRssKaM len=0 
' 0018     27 LABEL : Cell Value, String Constant - HMUXteZeKtGz len=0 
' 0018     24 LABEL : Cell Value, String Constant - igwDSYQCg len=0 
' 0018     27 LABEL : Cell Value, String Constant - ITPVRZijznBK len=0 
' 0018     24 LABEL : Cell Value, String Constant - KsVgQahrB len=0 
' 0018     23 LABEL : Cell Value, String Constant - LEVXWrkS len=0 
' 0018     24 LABEL : Cell Value, String Constant - LPwJHdvNp len=0 
' 0018     27 LABEL : Cell Value, String Constant - LUYvigiSGYGc len=0 
' 0018     24 LABEL : Cell Value, String Constant - mMiBfAnmr len=0 
' 0018     24 LABEL : Cell Value, String Constant - pvOxVNsLG len=0 
' 0018     24 LABEL : Cell Value, String Constant - RqUcBrwWy len=0 
' 0018     24 LABEL : Cell Value, String Constant - TbEtpOZIq len=0 
' 0018     21 LABEL : Cell Value, String Constant - UvEpWl len=0 
' 0018     22 LABEL : Cell Value, String Constant - YrhZwWM len=0 
' 0018     27 LABEL : Cell Value, String Constant - ZMXbQdXABBPC len=0 
' 0018     25 LABEL : Cell Value, String Constant - ZrXknNAcdn 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 Const
... (truncated)

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