Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 0735f4c0ec333c01…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:45:15 Authoring application: Microsoft Excel First seen: 2021-09-24
MD5: 59b81462982f2be83a8b9acaf41238b3 SHA-1: 461a97134d0211031a4daaa4ae4bc956421645cf SHA-256: 0735f4c0ec333c01287a490e064ddda865eadc18464e73f5018b11a87b82b8e4
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-enabled workbook detected as malicious. Critical heuristics indicate the presence of an Auto_Open defined name, which is a common technique for automatically executing macros upon opening the workbook. The macro sheet contains references to dangerous formula APIs, including RUN, suggesting it is designed to execute arbitrary code.

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) 6538 bytes
SHA-256: 8f6305fdb8704e094d5bedc8be3ec2648b85bdc38b761119198dbec1289115ba
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     19 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  PUrPdvTNKY
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H143 
' 0018     25 LABEL : Cell Value, String Constant - BjdJEmBmxn len=0 
' 0018     26 LABEL : Cell Value, String Constant - bpTieockGxE len=0 
' 0018     27 LABEL : Cell Value, String Constant - BTOnJjqfVwhf len=0 
' 0018     20 LABEL : Cell Value, String Constant - cadDJ len=0 
' 0018     21 LABEL : Cell Value, String Constant - EKIFlB len=0 
' 0018     20 LABEL : Cell Value, String Constant - Fuibs len=0 
' 0018     24 LABEL : Cell Value, String Constant - ghUqAVwWQ len=0 
' 0018     22 LABEL : Cell Value, String Constant - GkRhwuO len=0 
' 0018     25 LABEL : Cell Value, String Constant - HaidynmZYF len=0 
' 0018     20 LABEL : Cell Value, String Constant - KuDSu len=0 
' 0018     23 LABEL : Cell Value, String Constant - olJTifkI len=0 
' 0018     22 LABEL : Cell Value, String Constant - onvstYe len=0 
' 0018     23 LABEL : Cell Value, String Constant - pfCctXKd len=0 
' 0018     21 LABEL : Cell Value, String Constant - rBxMVa len=0 
' 0018     22 LABEL : Cell Value, String Constant - rYbtSjW len=0 
' 0018     20 LABEL : Cell Value, String Constant - uqxfL len=0 
' 0018     20 LABEL : Cell Value, String Constant - WCRiB len=0 
' 0018     22 LABEL : Cell Value, String Constant - YjKyPRl len=0 
' 0018     22 LABEL : Cell Value, String Constant - YtaxeqL len=0 
' 0018     23 LABEL : Cell Value, String Constant - ZnowiWHG 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 LABELSST : Cel
... (truncated)

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