Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 2f9d9fb207bad808…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:47:24 Authoring application: Microsoft Excel First seen: 2021-09-29
MD5: f187a8a8aab4277afd5375731879ec52 SHA-1: 15a76ada736916e9924e725d0e897e8708bb314a SHA-256: 2f9d9fb207bad8088688901f7873168475e4159ab68ac866b43aa8aa97986f99
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open function, which is a known method for executing malicious code. The presence of dangerous formula APIs like RUN indicates an intent to execute arbitrary commands. The macro sheet itself is heavily obfuscated, making it difficult to determine the exact payload, but the Auto_Open entry strongly suggests an attempt at initial execution.

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) 6832 bytes
SHA-256: f0fd0eb17baacb1e421579dae45ad403f971e227b48490ce7c974304fb63b2cc
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 -  ucYAfdlGjl
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I146 
' 0018     24 LABEL : Cell Value, String Constant - AyzCzrdBE len=0 
' 0018     24 LABEL : Cell Value, String Constant - BSJsnoTpI len=0 
' 0018     22 LABEL : Cell Value, String Constant - BtjuViG len=0 
' 0018     27 LABEL : Cell Value, String Constant - CCvNPdmcaaDa len=0 
' 0018     27 LABEL : Cell Value, String Constant - cYdNmQfYYGuQ len=0 
' 0018     22 LABEL : Cell Value, String Constant - CYucrjW len=0 
' 0018     26 LABEL : Cell Value, String Constant - EWVQHmWJGeJ len=0 
' 0018     21 LABEL : Cell Value, String Constant - fitqEc len=0 
' 0018     26 LABEL : Cell Value, String Constant - IlSQLyXSRKS len=0 
' 0018     22 LABEL : Cell Value, String Constant - IqIoRHo len=0 
' 0018     24 LABEL : Cell Value, String Constant - KwMnLvmqq len=0 
' 0018     21 LABEL : Cell Value, String Constant - kywQgm len=0 
' 0018     24 LABEL : Cell Value, String Constant - LbZrGxblz len=0 
' 0018     27 LABEL : Cell Value, String Constant - LkAlqJqmgONN len=0 
' 0018     20 LABEL : Cell Value, String Constant - MDUlU len=0 
' 0018     24 LABEL : Cell Value, String Constant - MTjVqKHlz len=0 
' 0018     22 LABEL : Cell Value, String Constant - pOIvyQD len=0 
' 0018     20 LABEL : Cell Value, String Constant - redcT len=0 
' 0018     24 LABEL : Cell Value, String Constant - wAKVjJMpI len=0 
' 0018     26 LABEL : Cell Value, String Constant - wPTnBicmmsl 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)

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