Malicious RTF — malware analysis report

Static analysis result for SHA-256 ff1d7b8125b85829…

MALICIOUS

RTF

428.2 KB First seen: 2019-03-18
MD5: 84c69f7aba4904ce41a15f7c858c4f8e SHA-1: 64f289e34427fad1bafe8eef5d171562b79a56d8 SHA-256: ff1d7b8125b85829783fe830bad545696252eb5616a10ca05ad0a5b00241a464
220 Risk Score

Malware Insights

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

The file is an RTF document containing embedded OLE object data, specifically triggering heuristics related to Equation Editor exploits and OLE activation. ClamAV identifies this as Rtf.Exploit.CVE_2017_11882-6584355-1, indicating a known exploit for client execution. The presence of OLE object data and the specific exploit signature strongly suggest the file's purpose is to leverage this vulnerability to execute a malicious payload, likely a downloader.

Heuristics 5

  • Equation Editor CLSID critical CVE likely RTF_EQUATION_EDITOR
    Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
  • 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.
  • ClamAV: Rtf.Exploit.CVE_2017_11882-6584355-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Rtf.Exploit.CVE_2017_11882-6584355-1
  • \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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000048e5.bin rtf-objdata-decoded RTF \objdata at offset 0x48E5 138661 bytes
SHA-256: f41a5005aa201740133a46dd16aa45829119071e2e5290fb1b940f710d58669c