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

Static analysis result for SHA-256 66b1c81f08c8dc54…

MALICIOUS

Office (OLE) / .XLS

76.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel
MD5: 5e35d6b84936fe6713eae86f0344b02a SHA-1: 9d954d33564c160aaf759a37d4263abfceeaaa76 SHA-256: 66b1c81f08c8dc54566b066c990edb24d0bdd946a503255d68ec2f66e85643db
120 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic

The sample is an Excel 4.0 (XLM) macro-enabled workbook that uses an Auto_Open macro to execute. It contains lures to trick the user into enabling macros, impersonating a document signing service. The macro attempts to download a file from multiple URLs, including 'stumbletrouser.com/hpbifbnnuauj/', and likely executes it using rundll32. The presence of XLM macros and the execution flow strongly suggest a downloader or droppper functionality.

Heuristics 4

  • 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.
  • 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.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • Document signing service impersonation lure medium SE_DOCUSIGN_LURE
    Document impersonates DocuSign, Adobe Sign, or a similar signing service in a signing-request context

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
95650bf3b083f7d7d2acad78646ed66bc3f66f931aabfdacd33cba28b47a33d6
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 2255 bytes