Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 8e953a3077a52d87…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:46:08 Authoring application: Microsoft Excel First seen: 2021-10-05
MD5: 0f9848e1f5418efa6f843ddd050ca8a6 SHA-1: 60bc10be07d453da42992b3706345d79d40da4ca SHA-256: 8e953a3077a52d87d344b82f7faf35fcce2f787d09726f9ffa7a859f83b4bf17
140 Risk Score

Malware Insights

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

The sample is an Excel file containing Excel 4.0 (XLM) macros, specifically triggering an Auto_Open macro. This indicates the file is designed to execute arbitrary code upon opening. The presence of dangerous formula APIs in the Auto_Open macro suggests it's intended to download and execute a secondary payload, a common technique for initial access and further compromise.

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) 6639 bytes
SHA-256: 55163cce3e5294e6421c61880dae820988d19b9510b7bd5c986288803be2d061
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     20 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  hvYZlASttkw
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F148 
' 0018     22 LABEL : Cell Value, String Constant - bHZJWBw len=0 
' 0018     27 LABEL : Cell Value, String Constant - cAbJLASsSeMF len=0 
' 0018     20 LABEL : Cell Value, String Constant - cDbmw len=0 
' 0018     25 LABEL : Cell Value, String Constant - DvSPGwBrFd len=0 
' 0018     22 LABEL : Cell Value, String Constant - EXORfhd len=0 
' 0018     21 LABEL : Cell Value, String Constant - fRDaRQ len=0 
' 0018     22 LABEL : Cell Value, String Constant - hFMrYWt len=0 
' 0018     25 LABEL : Cell Value, String Constant - iJDuMifwTr len=0 
' 0018     24 LABEL : Cell Value, String Constant - IYwmVLMRN len=0 
' 0018     25 LABEL : Cell Value, String Constant - kBgqCpwKLO len=0 
' 0018     21 LABEL : Cell Value, String Constant - LLxfuY len=0 
' 0018     25 LABEL : Cell Value, String Constant - OCyTZJAlHW len=0 
' 0018     25 LABEL : Cell Value, String Constant - PHKkJBtZyl len=0 
' 0018     26 LABEL : Cell Value, String Constant - snTGQiHuRpv len=0 
' 0018     27 LABEL : Cell Value, String Constant - SPZdqfvTGsPU len=0 
' 0018     21 LABEL : Cell Value, String Constant - sVMqFs len=0 
' 0018     20 LABEL : Cell Value, String Constant - trXCX len=0 
' 0018     27 LABEL : Cell Value, String Constant - UrdexJUDEyDr len=0 
' 0018     20 LABEL : Cell Value, String Constant - yCcWi len=0 
' 0018     26 LABEL : Cell Value, String Constant - YQGKAhUMHTb 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
' 00
... (truncated)