Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 678320758772567d…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:44:30 Authoring application: Microsoft Excel First seen: 2021-11-02
MD5: ada71639a71a837d09f7cfb413d8a94b SHA-1: 3dc004357382bca33ae4496b58e3c07144e183bf SHA-256: 678320758772567d87dd0321089985ec1072d98988afeecbf3ddf228e99a30af
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 that contains an Auto_Open entry, indicating it will execute macros automatically upon opening. Heuristics indicate the use of dangerous formula APIs, suggesting the macro is designed to execute arbitrary code. The presence of an Auto_Open entry and the use of dangerous functions strongly suggest the intent is 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) 6564 bytes
SHA-256: 1884058858262f45ea29adef0693cf9eeb9341afb5023dfd489ecb9543884d35
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 -  xFNx
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B142 
' 0018     24 LABEL : Cell Value, String Constant - dXyAfBgur len=0 
' 0018     27 LABEL : Cell Value, String Constant - ffvJfjBmeOIV len=0 
' 0018     20 LABEL : Cell Value, String Constant - hyGOH len=0 
' 0018     24 LABEL : Cell Value, String Constant - jlbdpLDCK len=0 
' 0018     22 LABEL : Cell Value, String Constant - kQdCnoL len=0 
' 0018     22 LABEL : Cell Value, String Constant - kRsAavw len=0 
' 0018     24 LABEL : Cell Value, String Constant - MaHKnjzml len=0 
' 0018     25 LABEL : Cell Value, String Constant - NAYvomNFQP len=0 
' 0018     20 LABEL : Cell Value, String Constant - NAZCQ len=0 
' 0018     22 LABEL : Cell Value, String Constant - NwJhurX len=0 
' 0018     22 LABEL : Cell Value, String Constant - OaSvZYc len=0 
' 0018     25 LABEL : Cell Value, String Constant - okqauGgmdZ len=0 
' 0018     20 LABEL : Cell Value, String Constant - OsOiR len=0 
' 0018     26 LABEL : Cell Value, String Constant - oysrWecNqpq len=0 
' 0018     26 LABEL : Cell Value, String Constant - pjlkdPjzCIe len=0 
' 0018     21 LABEL : Cell Value, String Constant - qsdQVX len=0 
' 0018     25 LABEL : Cell Value, String Constant - TAQFWmTqUC len=0 
' 0018     22 LABEL : Cell Value, String Constant - tBVHSic len=0 
' 0018     23 LABEL : Cell Value, String Constant - xTtZVqyM len=0 
' 0018     25 LABEL : Cell Value, String Constant - zzhnxdqaNs 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)