Malicious Office (OLE) / .XLS — malware analysis report

Static analysis result for SHA-256 a174abce368b7751…

MALICIOUS

Office (OLE) / .XLS

124.5 KB Created: 2020-09-20 21:17:44
MD5: 29c8b5edc30eadf757b72b0a14857903 SHA-1: 77d432fb96a0a453bae30107990c2c9ee0314330 SHA-256: a174abce368b775138c203d66fa8a3845aead2d53d87f220c58a2fe8ee7d9cf0
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

The Excel 4.0 macro sheet contains an Auto_Open entry that executes a PowerShell command. This command downloads a file from 'https://cutt.ly/qjdJoz4' and saves it as '12.exe' in the temporary directory, then executes it. The macro uses string concatenation to obfuscate the PowerShell command, including 'c' & CHAR(109) & 'd /c ' and 'o^wer^she^l^l'.

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
ed7e809d6fe009bed22ce7ce48d5a91c4a5c3d378f5abe2f88d44266b9136a86
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 1347 bytes