Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3b98ee2efcd5cffd…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:32:03 Authoring application: Microsoft Excel First seen: 2021-09-16
MD5: e9eb3e3a677345a1c39ef79ed8ffceed SHA-1: 03875b5f395bcd90612ded789aeb45508bd0fd36 SHA-256: 3b98ee2efcd5cffd99a7be136b6aeb0ff45760fca5446afefb3ed8f3b0b9b939
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, indicated by the OLE_XLM_AUTOOPEN and OLE_XLM_DANGEROUS_FN heuristics. The presence of an Auto_Open defined name suggests that the macro will execute automatically upon opening the workbook. The dangerous formula APIs used in the macro indicate it is designed to perform malicious actions, such as downloading and executing a second-stage 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) 6583 bytes
SHA-256: de3293d110e62e69a6826d2920136f69f51795cdbe21f56bab852dd1b67b85cf
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     17 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  NnaJvRLq
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F139 
' 0018     20 LABEL : Cell Value, String Constant - bFHPf len=0 
' 0018     24 LABEL : Cell Value, String Constant - CDxUYcxsR len=0 
' 0018     25 LABEL : Cell Value, String Constant - CInrjIOoPA len=0 
' 0018     26 LABEL : Cell Value, String Constant - FAfaaPqYYMf len=0 
' 0018     24 LABEL : Cell Value, String Constant - IngHfFgJD len=0 
' 0018     26 LABEL : Cell Value, String Constant - IrrAegtbeTL len=0 
' 0018     24 LABEL : Cell Value, String Constant - LoujUWLiq len=0 
' 0018     24 LABEL : Cell Value, String Constant - LWqiUrCFl len=0 
' 0018     25 LABEL : Cell Value, String Constant - mEvFLPdbYL len=0 
' 0018     20 LABEL : Cell Value, String Constant - rKEyh len=0 
' 0018     23 LABEL : Cell Value, String Constant - RPQCFKOR len=0 
' 0018     27 LABEL : Cell Value, String Constant - SoarofgCFuMW len=0 
' 0018     21 LABEL : Cell Value, String Constant - sOPfmz len=0 
' 0018     20 LABEL : Cell Value, String Constant - tsXIh len=0 
' 0018     22 LABEL : Cell Value, String Constant - TxAejxE len=0 
' 0018     20 LABEL : Cell Value, String Constant - UyacA len=0 
' 0018     26 LABEL : Cell Value, String Constant - VWCguDXUUEd len=0 
' 0018     22 LABEL : Cell Value, String Constant - wcfaFqM len=0 
' 0018     20 LABEL : Cell Value, String Constant - XSOqu len=0 
' 0018     27 LABEL : Cell Value, String Constant - yQLIrllDxuGB 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     1
... (truncated)

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