RTF malware analysis — malicious · 62b720cfb1c69f4b

MALICIOUS

RTF

814.5 KB First seen: 2020-09-15

MD5: 8823f3efc24472eb77bedf4d03855b21 SHA-1: 3aa0a9adcdeafbdc8e3d70371b67caf7c1059297 SHA-256: 62b720cfb1c69f4b21f4bd55c8e7fa1cfd71da081db1afbbed005dfc010c9bfb

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 that triggers CVE-2017-11882 through the Equation Editor. This exploit is designed to execute arbitrary code, likely a second-stage payload, as indicated by the 'Suspicious extracted artifact' heuristic firing with shellcode indicators. The embedded URL, though marked benign, is often used in such attack chains.

Heuristics 7

Obfuscated Equation Editor ProgID + activation critical CVE related RTF_EQUATION_EDITOR

RTF decodes to an Equation.3 ProgID from top-level \objdata hex after nested RTF junk groups are ignored, and the document also contains \objemb plus \objupdate activation. This is an obfuscated Equation Editor exploit surface associated with CVE-2017-11882 / CVE-2018-0802 families, but no exact malformed MTEF CVE primitive was recovered from this object.
Equation Editor activation — CVE-2017-11882 related high CVE related CVE_2017_11882_ACTIVATION_RELATED

RTF decodes to an Equation.3 ProgID and requests OLE activation with \objemb plus \objupdate. This reaches the legacy Equation Editor attack surface used by CVE-2017-11882/CVE-2018-0802 documents, but the malformed MTEF/native payload needed for stronger attribution was not recovered.
Suspicious extracted artifact critical 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.
\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
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://bit.ly/3bERRvh In RTF body

Extracted artifacts 1

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`objdata_00_off000ca49a.bin`	rtf-objdata-decoded	RTF \objdata at offset 0xCA49A	1456 bytes
SHA-256: `8f1a149a87e35d107d84f97f92d74cc2fabe6f0fcda996cc8deb2e8eaacb46fb`
Detection ClamAV: No threats found Obfuscation or payload: likely Static shellcode analysis recovered URL(s): http://bit.ly/3bERRvh Static shellcode analysis found candidate code region(s). Indicators: SC_STR_LOADLIBRARY, SC_STR_URLDOWNLOAD, SC_PEB_ACCESS Static shellcode analysis recovered API/import strings: LoadLibraryA, GetProcAddress, CreateProcessA, URLDownloadToFileA, ExitProcess

Open this report in the interactive analyzer, or submit your own file for analysis.