Malicious RTF — malware analysis report

Static analysis result for SHA-256 ff5e30affc084008…

MALICIOUS

RTF

152.5 KB First seen: 2024-06-25
MD5: 6476133e6fcd5bb5fad7d39d1d214a6a SHA-1: 5fd4049d53c0dc633d265dc78d3309c82b1dbdc0 SHA-256: ff5e30affc0840089daf129df7941e688b8c1a32838f5b27d52c79acca81c9bd
180 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 User Execution: Malicious File T1566.001 Phishing: Spearphishing Attachment

The RTF file contains an embedded OLE object that leverages the Equation Editor vulnerability (CVE-2017-11882). The presence of `RTF_OBJDATA`, `RTF_OBJEMB`, `CVE_2017_11882_EQUATION_OLE10NATIVE`, `RTF_OBJUPDATE`, and `RTF_OLE10NATIVE_STREAM` heuristics strongly indicates exploitation of this known vulnerability. The decoded OLE object data suggests it's designed to execute a malicious payload, likely a downloader.

Heuristics 5

  • Equation Editor Ole10Native payload — CVE-2017-11882 likely critical CVE likely CVE_2017_11882_EQUATION_OLE10NATIVE
    RTF decodes to an activated Microsoft Equation 3.0 OLE storage whose payload is a high-entropy Ole10Native stream rather than normal Equation Native/MTEF data. This is a weaponized Equation Editor RCE delivery shape consistent with CVE-2017-11882/CVE-2018-0802.
  • Ole10Native stream in RTF OLE object high CVE related RTF_OLE10NATIVE_STREAM
    RTF contains an embedded OLE object with an Ole10Native stream. This is a strong payload-container signal and is related to Word/OLE exploit delivery, but it is not specific enough on its own to assign a CVE.
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000016a3.bin
f4c522cd613d9aff250f56739db174823749e0d5b9ea8a611c913fa459c04ade
rtf-objdata-decoded RTF \objdata at offset 0x16A3 4164 bytes