Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 30ddd34ad9458335…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:40:53 Authoring application: Microsoft Excel First seen: 2021-06-20
MD5: 2221b8bfba830a6b4de153ff42bb2d6e SHA-1: 1f8a566d786ac7bf379ff16204d42e49a5e5e4e0 SHA-256: 30ddd34ad9458335e908ba1c11f19052554bcb0a802d7fad39ca998256a52c54
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 finding indicating automatic execution upon opening. The presence of dangerous formula APIs further suggests malicious intent. The macro sheet itself is named 'vxB', and the Auto_Open function is designed to execute arbitrary code, likely leading to further stages of infection.

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) 6554 bytes
SHA-256: c9b9d23bec863453892604e59f513666d3ea372bb3f51cb46e380cd16e84312a
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     12 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  vxB
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!G164 
' 0018     21 LABEL : Cell Value, String Constant - CKiHGP len=0 
' 0018     22 LABEL : Cell Value, String Constant - CkrZflF len=0 
' 0018     25 LABEL : Cell Value, String Constant - eAVRWUdufB len=0 
' 0018     21 LABEL : Cell Value, String Constant - GVmPYe len=0 
' 0018     24 LABEL : Cell Value, String Constant - HUAmQzbuw len=0 
' 0018     23 LABEL : Cell Value, String Constant - hvMfluVE len=0 
' 0018     21 LABEL : Cell Value, String Constant - iJMxLr len=0 
' 0018     25 LABEL : Cell Value, String Constant - KOguRPMaqH len=0 
' 0018     21 LABEL : Cell Value, String Constant - KpLwKN len=0 
' 0018     26 LABEL : Cell Value, String Constant - LzinIMupAUD len=0 
' 0018     25 LABEL : Cell Value, String Constant - NRPmGkbPCo len=0 
' 0018     26 LABEL : Cell Value, String Constant - oKrxNOdJmcF len=0 
' 0018     23 LABEL : Cell Value, String Constant - QWukQKxv len=0 
' 0018     22 LABEL : Cell Value, String Constant - SlTxbMs len=0 
' 0018     21 LABEL : Cell Value, String Constant - tiKhcT len=0 
' 0018     24 LABEL : Cell Value, String Constant - WuFrdmNGx len=0 
' 0018     23 LABEL : Cell Value, String Constant - XdZqbbrZ len=0 
' 0018     27 LABEL : Cell Value, String Constant - xtRyCyzSwZLG len=0 
' 0018     25 LABEL : Cell Value, String Constant - ynvuDIJvIq len=0 
' 0018     24 LABEL : Cell Value, String Constant - ZOZzbRXci 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 
... (truncated)

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