Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b12f3fcf1bafacaf…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:43:31 Authoring application: Microsoft Excel First seen: 2021-10-12
MD5: d5a14daa34f7215b15b791eebcbf665d SHA-1: 726d792b474cd5de7eef2adf49e18b49c20e34c9 SHA-256: b12f3fcf1bafacaf66cd6e9f975a5cdaabf4e5b657764aa3e0d151a02a763731
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical indicator of malicious intent. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary code. Without further deobfuscation or network activity, the exact payload and family remain unknown.

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) 6691 bytes
SHA-256: 1e16adfbd9d4b584e6a8360491eb9ad57412d8499dfd3409e78265b7f0e7c7a0
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 -  ZduJimX
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H184 
' 0018     20 LABEL : Cell Value, String Constant - fCVZZ len=0 
' 0018     21 LABEL : Cell Value, String Constant - FNXhHB len=0 
' 0018     23 LABEL : Cell Value, String Constant - HKgNeCFR len=0 
' 0018     25 LABEL : Cell Value, String Constant - jelfVDLfHt len=0 
' 0018     23 LABEL : Cell Value, String Constant - LKPUgujS len=0 
' 0018     20 LABEL : Cell Value, String Constant - lxPoK len=0 
' 0018     24 LABEL : Cell Value, String Constant - MkjsCIlBM len=0 
' 0018     23 LABEL : Cell Value, String Constant - MvSUglpW len=0 
' 0018     26 LABEL : Cell Value, String Constant - NiNSZbVewtw len=0 
' 0018     24 LABEL : Cell Value, String Constant - nQUuLxPiX len=0 
' 0018     20 LABEL : Cell Value, String Constant - paXim len=0 
' 0018     23 LABEL : Cell Value, String Constant - pIFyPjPB len=0 
' 0018     23 LABEL : Cell Value, String Constant - QTTvNlLA len=0 
' 0018     22 LABEL : Cell Value, String Constant - qUkAmKh len=0 
' 0018     27 LABEL : Cell Value, String Constant - RdAlPoqHDpZB len=0 
' 0018     25 LABEL : Cell Value, String Constant - tGOMAxCJeR len=0 
' 0018     26 LABEL : Cell Value, String Constant - wFZkDjftRWJ len=0 
' 0018     25 LABEL : Cell Value, String Constant - wJKXVxHCDx len=0 
' 0018     20 LABEL : Cell Value, String Constant - XcKvm len=0 
' 0018     22 LABEL : Cell Value, String Constant - YVoJOhU 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     10 LAB
... (truncated)

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