Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 a7a6d9e2bd6a1c34…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:29:38 Authoring application: Microsoft Excel First seen: 2021-09-18
MD5: b02a7bff85c72b99fe662dbe3f44778b SHA-1: 38967f796996139f90ce4f63c12c29673e0f09ac SHA-256: a7a6d9e2bd6a1c346fe9d477dd33648067ae9a6eac274f6d048beb5635524b30
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 entry, which is a critical indicator of malicious intent. The presence of dangerous formula APIs like RUN in the Auto_Open macro suggests the execution of arbitrary code. This technique is commonly used to download and execute further stages of malware.

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) 6655 bytes
SHA-256: 15eae335cfa069a524d158ac144406d9cf6dfe917f361d705efad6799fe92686
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     18 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  KOaZujkWJ
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A193 
' 0018     20 LABEL : Cell Value, String Constant - EfuPl len=0 
' 0018     23 LABEL : Cell Value, String Constant - gPvjseZC len=0 
' 0018     27 LABEL : Cell Value, String Constant - iuGskdeFsjwU len=0 
' 0018     26 LABEL : Cell Value, String Constant - IWkzjPMxIUc len=0 
' 0018     21 LABEL : Cell Value, String Constant - JFwOrj len=0 
' 0018     22 LABEL : Cell Value, String Constant - jpnkJHO len=0 
' 0018     25 LABEL : Cell Value, String Constant - looMkcAwmL len=0 
' 0018     21 LABEL : Cell Value, String Constant - mhBdzt len=0 
' 0018     25 LABEL : Cell Value, String Constant - mQfNhvNpnE len=0 
' 0018     26 LABEL : Cell Value, String Constant - mxiWAbLwtmq len=0 
' 0018     24 LABEL : Cell Value, String Constant - oThgGrAuX len=0 
' 0018     21 LABEL : Cell Value, String Constant - PPfmel len=0 
' 0018     22 LABEL : Cell Value, String Constant - PumOiie len=0 
' 0018     26 LABEL : Cell Value, String Constant - qiqmlsVJIcj len=0 
' 0018     20 LABEL : Cell Value, String Constant - QwJet len=0 
' 0018     24 LABEL : Cell Value, String Constant - uhQAKXyhk len=0 
' 0018     27 LABEL : Cell Value, String Constant - XiyzuSHxosHS len=0 
' 0018     23 LABEL : Cell Value, String Constant - yLWuYjer len=0 
' 0018     23 LABEL : Cell Value, String Constant - ZdqDoBSl len=0 
' 0018     24 LABEL : Cell Value, String Constant - ZEGlJZVTf 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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