Malicious RTF — malware analysis report

Static analysis result for SHA-256 0b691b8e535718c9…

MALICIOUS

RTF

14.4 KB First seen: 2018-09-04
MD5: 83825fb4fca63c0c4e416a37f42831d5 SHA-1: 8eb663f8b398f0f0d4210c19e447717ccc822f5d SHA-256: 0b691b8e535718c9e3425ac476052ebe04eedacf262e9ae8bad96a28c1ac1b48
180 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The sample is an RTF document that contains an embedded OLE object. Heuristics indicate the exploitation of CVE-2017-11882 via the Equation Editor, a common method for achieving arbitrary code execution. This technique is often used to download and execute further malicious content, hence the likely attack pattern.

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_off0000090a.bin rtf-objdata-decoded RTF \objdata at offset 0x90A 4130 bytes
SHA-256: d4eccfa47746897f3975732390f16611bc8ffb8de7c65986fb740523c637813e