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

Static analysis result for SHA-256 6c127c5bf98fca58…

MALICIOUS

Office (OLE) / .XLS

103.1 KB Authoring application: Microsoft Excel
MD5: f168a06bbec90374a7199d228e8d6e10 SHA-1: 0292a220b7efe2983ea2072563ff14ff137cc58e SHA-256: 6c127c5bf98fca58049bd5a17fca78217c2fb9a561927b619795b7d27ff4c412
188 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1027 Obfuscated Files or Information T1071.001 Web Protocols T1105 Ingress Tool Transfer

The file is an Excel spreadsheet containing VBA macros. Heuristics indicate the presence of obfuscated strings and API hash resolution, suggesting the macro attempts to hide its functionality. The 'OLE_VBA_MACROS' heuristic firing with 'no executable statements' is misleading, as the other heuristics point to malicious activity. The likely intent is to download and execute a second-stage payload, but no specific URLs or commands were extracted.

Heuristics 5

  • XOR-encoded strings (key 0xFF) critical SC_XOR_ENCODED
    Found 4 Windows library/API name(s) XOR-encoded with single-byte key 0xFF: 'kernel32.dll', 'advapi32.dll', 'KERNEL32.DLL', 'ADVAPI32.DLL'
  • x86 GetPC stub (CALL $+5; POP EBX) high SC_GETPC_CALL
    x86 GetPC stub (CALL $+5; POP EBX)
  • PEB access via FS segment (x86) high SC_PEB_ACCESS
    PEB access via FS segment (x86)
  • PEB API-hash resolver high SC_API_HASH_RESOLVER
    PEB access followed by ROR13-style API hashing, a common position-independent shellcode import resolver
  • VBA project contains no executable statements low OLE_VBA_MACROS
    Document contains a VBA project, but extracted modules only contain attributes/options/comments and no executable statements.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
481031c20227961d1e7d207d0bb17c79a9001efbdb37ac509a4ff93acb047bf0
vba-macro oletools.olevba.extract_macros (decoded VBA source) 606 bytes