Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b81949d348944aa0…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:40:07 Authoring application: Microsoft Excel First seen: 2021-06-30
MD5: ccb8fc281e8ccf7679e49339e2acf0e0 SHA-1: 7a535ca4988602d3ef89337870ed8684bd21de2a SHA-256: b81949d348944aa00df880bae348b8f3f6ca8305ce825f831094e78d4df71dec
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 arbitrary code upon opening the workbook. The presence of dangerous formula APIs like RUN indicates the macro is intended to download and execute a secondary payload, a common technique for malware delivery.

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) 6598 bytes
SHA-256: 6f093ac92ecd6ae9de89b4cebb063830b3c7c10c55e2a1d53aa99fb17c9778e0
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 -  nBLuypIyf
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H143 
' 0018     22 LABEL : Cell Value, String Constant - cICLWvy len=0 
' 0018     23 LABEL : Cell Value, String Constant - DGZdaCaV len=0 
' 0018     27 LABEL : Cell Value, String Constant - gNTiUvujXupD len=0 
' 0018     24 LABEL : Cell Value, String Constant - hmwRBLQMi len=0 
' 0018     22 LABEL : Cell Value, String Constant - HTqnwhf len=0 
' 0018     20 LABEL : Cell Value, String Constant - HxuCK len=0 
' 0018     26 LABEL : Cell Value, String Constant - iUSGqsMRzjm len=0 
' 0018     20 LABEL : Cell Value, String Constant - KrFCu len=0 
' 0018     24 LABEL : Cell Value, String Constant - ltrnrwxJy len=0 
' 0018     27 LABEL : Cell Value, String Constant - NLlaskQvmnrC len=0 
' 0018     22 LABEL : Cell Value, String Constant - ptbxjap len=0 
' 0018     24 LABEL : Cell Value, String Constant - qqXTkXHrj len=0 
' 0018     27 LABEL : Cell Value, String Constant - qyKvFelwGAkc len=0 
' 0018     27 LABEL : Cell Value, String Constant - rmxxFkhICWyS len=0 
' 0018     25 LABEL : Cell Value, String Constant - rZigTDFRiI len=0 
' 0018     26 LABEL : Cell Value, String Constant - SqhfyXyAykZ len=0 
' 0018     25 LABEL : Cell Value, String Constant - uffkLvFjVT len=0 
' 0018     20 LABEL : Cell Value, String Constant - Vktod len=0 
' 0018     25 LABEL : Cell Value, String Constant - WxXHbktbMn len=0 
' 0018     23 LABEL : Cell Value, String Constant - YgBDkryM 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/ SS
... (truncated)

Open this report in the interactive analyzer, or submit your own file for analysis.