Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4779d53cedde0b94…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:47:36 Authoring application: Microsoft Excel First seen: 2021-07-10
MD5: edf03b83e71074106d5a75b6516b4e15 SHA-1: bd8139b97da767c77a689642c1efff48a40f5c77 SHA-256: 4779d53cedde0b942eb8e380cb3b8d5ebd19cbe40c0435353e705a26f23dae75
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 (XLM) macros. Heuristics indicate the presence of an Auto_Open macro, which is a common technique for executing malicious code upon opening the workbook. The macro sheet contains a call to a dangerous function, likely intended to download and execute 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) 6829 bytes
SHA-256: b89adeef8721aa01b3d8ddc0885b97e177ae09f9382b4a82bd327aa4e368e0af
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 -  WakxkLms
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B183 
' 0018     27 LABEL : Cell Value, String Constant - DjNwZDCnxGrb len=0 
' 0018     21 LABEL : Cell Value, String Constant - FdSIri len=0 
' 0018     24 LABEL : Cell Value, String Constant - fOSiBDbwt len=0 
' 0018     25 LABEL : Cell Value, String Constant - GZPAYjhxsY len=0 
' 0018     26 LABEL : Cell Value, String Constant - HCxlNuSLxce len=0 
' 0018     27 LABEL : Cell Value, String Constant - ioTYCEcYyVZQ len=0 
' 0018     20 LABEL : Cell Value, String Constant - jnZgm len=0 
' 0018     20 LABEL : Cell Value, String Constant - jsmTB len=0 
' 0018     25 LABEL : Cell Value, String Constant - krqsrJVwQj len=0 
' 0018     20 LABEL : Cell Value, String Constant - LSeOk len=0 
' 0018     25 LABEL : Cell Value, String Constant - lsuQBudLvU len=0 
' 0018     27 LABEL : Cell Value, String Constant - nARzZJenDjfp len=0 
' 0018     26 LABEL : Cell Value, String Constant - oJYZOFQTVpD len=0 
' 0018     26 LABEL : Cell Value, String Constant - rSBdWJtviWR len=0 
' 0018     27 LABEL : Cell Value, String Constant - VABKCySANveP len=0 
' 0018     24 LABEL : Cell Value, String Constant - WGRyXLtmd len=0 
' 0018     27 LABEL : Cell Value, String Constant - wzuYAtXMmOBt len=0 
' 0018     24 LABEL : Cell Value, String Constant - XfDkAvpUJ len=0 
' 0018     22 LABEL : Cell Value, String Constant - XlxKdQG len=0 
' 0018     27 LABEL : Cell Value, String Constant - yfFsbRpfUCAj 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 Co
... (truncated)

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