Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 1c8e535bf5abcbd7…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:38:16 Authoring application: Microsoft Excel First seen: 2021-05-26
MD5: 83580f3d26caf7c66d7f109449507837 SHA-1: 2582aab5a8847a9a8712db7d0a9f06bb693bd4db SHA-256: 1c8e535bf5abcbd751a3d86595d9d21a56a85dbf28fa792391a424f2d360f2f4
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 (XLM) macros, specifically an Auto_Open entry, which is a critical finding. This indicates the macro sheet is designed to automatically execute code upon opening the workbook. The presence of dangerous formula APIs like RUN suggests the macro is intended to execute a payload, likely a downloader for a second-stage malicious file. No specific family could be identified.

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) 6700 bytes
SHA-256: ec2aeb2cc3bbe659e5a03e93468caf4a8f15c7627f92c81804a0964f218906bb
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 -  iDzIHIj
' 0018     23 LABEL : Cell Value, String Constant - AghypUiU len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B149 
' 0018     22 LABEL : Cell Value, String Constant - BSROWAA len=0 
' 0018     26 LABEL : Cell Value, String Constant - CHkGrdMXSYm len=0 
' 0018     24 LABEL : Cell Value, String Constant - eGKvvoXYz len=0 
' 0018     25 LABEL : Cell Value, String Constant - EyjOsinNxx len=0 
' 0018     23 LABEL : Cell Value, String Constant - FqYRxJnp len=0 
' 0018     21 LABEL : Cell Value, String Constant - GMjIOS len=0 
' 0018     20 LABEL : Cell Value, String Constant - hcseY len=0 
' 0018     27 LABEL : Cell Value, String Constant - hdEamJfwAmQZ len=0 
' 0018     22 LABEL : Cell Value, String Constant - jdkrKar len=0 
' 0018     23 LABEL : Cell Value, String Constant - KTPNEaiQ len=0 
' 0018     20 LABEL : Cell Value, String Constant - lOhcw len=0 
' 0018     24 LABEL : Cell Value, String Constant - LVdwRKxgH len=0 
' 0018     26 LABEL : Cell Value, String Constant - qPoXXyuDOZJ len=0 
' 0018     26 LABEL : Cell Value, String Constant - QqxAdwZMHrG len=0 
' 0018     20 LABEL : Cell Value, String Constant - vqTig len=0 
' 0018     21 LABEL : Cell Value, String Constant - xARXgG len=0 
' 0018     23 LABEL : Cell Value, String Constant - XowJaWxe len=0 
' 0018     26 LABEL : Cell Value, String Constant - xSbykDjKawU len=0 
' 0018     27 LABEL : Cell Value, String Constant - zJwaYRfKATFZ 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    
... (truncated)

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