Malicious RTF — malware analysis report

Static analysis result for SHA-256 e4d60b3c6cac2739…

MALICIOUS

RTF

75.5 KB First seen: 2018-08-05
MD5: afcca25f26f54c12b064a5801e80c6b5 SHA-1: 21e6f7771867eca7031166b072fdafd7271de4d4 SHA-256: e4d60b3c6cac2739884193dfd5ad9d0b74d9588eef292cfbac9c517d5a9b9348
242 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object with data indicative of the Equation Editor vulnerability (CVE-2017-11882). This vulnerability allows for the execution of arbitrary code, likely to download and run a second-stage payload from the identified URL. The presence of shellcode API strings further supports this exploitation vector.

Heuristics 7

  • 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
  • Suspicious extracted artifact medium EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://uploadtops.is/1//q/AWtSsv3 In RTF body

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000bbc.bin rtf-objdata-decoded RTF \objdata at offset 0xBBC 23257 bytes
SHA-256: 5b6ec49f7e54aea61694056cadae3c4675fd469acb221ee3f5c32a0f020a3be3
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis found candidate code region(s). Indicators: SC_GETPC_CALL, SC_PEB_ACCESS, SC_GETPC_CALL Static shellcode analysis recovered API/import strings: LoadLibraryA, GetProcAddress, ExitProcess, URLDownloadToFileA, ShellExecuteA