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

Static analysis result for SHA-256 91f1c16c1340d0d1…

MALICIOUS

Office (OLE) / .XLS

367.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 857f7bb41777a72ff9f794a732856d3b SHA-1: fa1941a8d1e5d74969079c0c3a9f46e0f673c994 SHA-256: 91f1c16c1340d0d17fe8468acfba6d8635c111a03ea37bf51f84c7eb96f4981f
102 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File

The sample is an Excel 4.0 (XLM) macro-enabled spreadsheet. It contains an Auto_Open macro, which is a common technique to execute malicious code upon opening the document. The document body and extracted macros indicate an attempt to lure the user into enabling macros. The XLM macros contain concatenated strings that reconstruct two URLs, which are likely used to download and execute a second-stage payload.

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
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://escolamundoazul.com.br/ntmQmwXnc6KC/ue.html
    • https://laresumeservice.com/wp7rTKrY/ue.html

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
e0f9b32b2cf7d5bbad99732afb6eb8bf95619170305ebee6a87504bc690cca2a
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8209 bytes