Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 d7fde723e1e6a071…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:32:58 Authoring application: Microsoft Excel First seen: 2020-12-25
MD5: 05e058dc710b2490ee981d0bba2ed380 SHA-1: 87e9db1ea81d389b1292cb439770558dc88c8cdf SHA-256: d7fde723e1e6a0711b2d02639231376845ff988c288ab1556b35e17944e14184
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 containing an Auto_Open defined name, indicating it will execute macros automatically upon opening. Heuristics indicate the use of dangerous formula APIs, specifically the RUN function, which allows for arbitrary command execution. The presence of an Auto_Open entry strongly suggests the intent to execute a malicious 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) 6466 bytes
SHA-256: f1a11551d1b022ff3171f1f11cf1c247fc1596485f6f42b73bb9a0857bebb1b7
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  fIfNR
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!D165 
' 0018     27 LABEL : Cell Value, String Constant - bfWJwuuRzXEj len=0 
' 0018     20 LABEL : Cell Value, String Constant - bnNsE len=0 
' 0018     27 LABEL : Cell Value, String Constant - chYHRgwyFvRv len=0 
' 0018     24 LABEL : Cell Value, String Constant - EChcXwppA len=0 
' 0018     26 LABEL : Cell Value, String Constant - EdlAQJRHQQh len=0 
' 0018     26 LABEL : Cell Value, String Constant - hhEiwGsfGMQ len=0 
' 0018     20 LABEL : Cell Value, String Constant - iVEPV len=0 
' 0018     23 LABEL : Cell Value, String Constant - KiEZKATK len=0 
' 0018     21 LABEL : Cell Value, String Constant - KsQmFE len=0 
' 0018     27 LABEL : Cell Value, String Constant - lIBBciAVKeLO len=0 
' 0018     21 LABEL : Cell Value, String Constant - LYRzUL len=0 
' 0018     20 LABEL : Cell Value, String Constant - mWObT len=0 
' 0018     25 LABEL : Cell Value, String Constant - nqzxBSGPRW len=0 
' 0018     23 LABEL : Cell Value, String Constant - OANdyJnm len=0 
' 0018     21 LABEL : Cell Value, String Constant - QYiGoM len=0 
' 0018     26 LABEL : Cell Value, String Constant - rbmkwSCJzDn len=0 
' 0018     27 LABEL : Cell Value, String Constant - SMuRxOOMZLSP len=0 
' 0018     25 LABEL : Cell Value, String Constant - WYrrRcNGFS len=0 
' 0018     24 LABEL : Cell Value, String Constant - ZBRXwXYye len=0 
' 0018     25 LABEL : Cell Value, String Constant - zsPIpZPvWF 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
' 0
... (truncated)