Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 0bf8eea7c3b5dcb9…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:36:21 Authoring application: Microsoft Excel First seen: 2021-06-13
MD5: 34419189cf39389d34f9a161a2aac1cd SHA-1: 39038a45936733aa2f0fc5b50bc544d6293354f4 SHA-256: 0bf8eea7c3b5dcb99fa1a35f50c78f905de855dd08923bf2694b7e64e77922ef
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 macros, specifically an Auto_Open function. This function is designed to execute automatically when the workbook is opened, indicating a likely attempt to run malicious code. The presence of dangerous formula APIs in the Auto_Open macro further increases the suspicion of malicious intent.

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) 6574 bytes
SHA-256: 502e042b6be564f9ea667016cd6553a86c51d104ee216b7e98ab309cee2f14b2
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 -  UWYlhbmGk
' 0018     23 LABEL : Cell Value, String Constant - abHHyUdT len=0 
' 0018     20 LABEL : Cell Value, String Constant - aNNwm len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B165 
' 0018     25 LABEL : Cell Value, String Constant - cHsoNoPgeL len=0 
' 0018     21 LABEL : Cell Value, String Constant - DjPLFD len=0 
' 0018     26 LABEL : Cell Value, String Constant - ePDZHFGQRYP len=0 
' 0018     22 LABEL : Cell Value, String Constant - fCPfpBy len=0 
' 0018     24 LABEL : Cell Value, String Constant - FYGOFXbqk len=0 
' 0018     20 LABEL : Cell Value, String Constant - GDYBE len=0 
' 0018     24 LABEL : Cell Value, String Constant - gLBObctbt len=0 
' 0018     21 LABEL : Cell Value, String Constant - hkludV len=0 
' 0018     20 LABEL : Cell Value, String Constant - lPxnI len=0 
' 0018     24 LABEL : Cell Value, String Constant - pMwchWwBP len=0 
' 0018     27 LABEL : Cell Value, String Constant - SCoMIgokajZR len=0 
' 0018     25 LABEL : Cell Value, String Constant - SqTuaOnbVH len=0 
' 0018     24 LABEL : Cell Value, String Constant - ssoaPVSJh len=0 
' 0018     24 LABEL : Cell Value, String Constant - tOuBzQvqm len=0 
' 0018     24 LABEL : Cell Value, String Constant - UqpaQJWnx len=0 
' 0018     25 LABEL : Cell Value, String Constant - wQFqAzAxVd len=0 
' 0018     26 LABEL : Cell Value, String Constant - zEltGwadjrr len=0 
' 0018     22 LABEL : Cell Value, String Constant - ZUUWoCk 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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