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

Static analysis result for SHA-256 67e48dd4e869a222…

MALICIOUS

Office (OLE) / ._SL

241.0 KB
MD5: 2e724e86f9fdc30405faa294411c1e2a SHA-1: d6317a54424c3f3df9a12bf5c337591d81a9314a SHA-256: 67e48dd4e869a22261d922dd5048e2fe84b5891587d1931e88209f2361b32e0b
180 Risk Score

Malware Insights

MITRE ATT&CK
T1027 Obfuscated Files or Information T1566.001 Spearphishing Attachment

The sample exhibits characteristics of a malicious Office document, including the presence of embedded objects and the use of XOR-encoded strings. The large slack space in the OLE structure and the embedded EMF object are also suspicious indicators. While the document body is in Chinese and appears to be test-related, the overall structure and encoding point towards a potential payload delivery mechanism, likely via spearphishing.

Heuristics 4

  • Office EPRINT stream contains EMF object high CVE related OLE_EPRINT_EMF_OBJECT
    OLE ObjectPool contains an EPRINT stream with EMF data. This is rare in normal documents and is CVE-2007-3893/MS07-046-family evidence when paired with Office exploit payload anomalies, but the malformed EMF record is not proven by this rule alone.
  • XOR-encoded strings (key 0x81) critical SC_XOR_ENCODED
    Found 8 Windows library/API name(s) XOR-encoded with single-byte key 0x81: 'kernel32.dll', 'kernel32.dll', 'kernel32.dll', 'kernel32.dll', 'advapi32.dll', 'advapi32.dll', 'KERNEL32.DLL', 'LoadLibraryA'
  • PEB access via FS segment (x86) high SC_PEB_ACCESS
    PEB access via FS segment (x86)
  • OLE document has large unaccounted-for region high OLE_SLACK_ANOMALY
    OLE file is 246,788 bytes but its declared streams total only 60,708 bytes — 186,080 bytes (75%) live in unallocated sector slack. This is the canonical hiding place for pre-macro-era Office exploit payloads (XOR-encoded shellcode reached via a parser pointer-corruption bug in the document structure).