Emodldr RTF malware analysis — malicious · efc27e99c9f65d7d

MALICIOUS

RTF

1.78 MB Created: 2018-09-28 15:38:00 First seen: 2019-02-10

MD5: 247e052d50cc182b4cf05d2da50ab3f7 SHA-1: 4295a1a7e3205e7e48959e3b30f289a366d97d68 SHA-256: efc27e99c9f65d7d3222479a36231ac65498396786c6c1dc87f4c24eb5d86585

322 Risk Score

Malware Insights

Emodldr · confidence 95%

MITRE ATT&CK

T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The RTF file contains multiple embedded OLE objects with excessive hex-encoded data, and a critical heuristic firing for CVE-2017-8759 indicates exploitation of MSXML SAX OLE activation. This suggests the file is designed to exploit this vulnerability to execute arbitrary code, likely downloading and running a second-stage payload. The ClamAV detection as 'Xls.Malware.Emodldr' further supports this assessment.

Heuristics 9

CVE-2017-8759 — MSXML SAX OLE activation critical CVE likely CVE_2017_8759

RTF contains a hex-encoded OLE1 object for Msxml2.SAXXMLReader.6.0 followed by an embedded OLE compound document, and the document requests OLE activation. This matches the RTF staging shape used for CVE-2017-8759 SOAP/WSDL parser code injection.
Composite Moniker in RTF OLE object high CVE related RTF_COMPOSITE_MONIKER_RELATED

RTF contains Composite Moniker CLSID in OLE object context, but no nearby scriptlet/SCT payload was confirmed. Treat as related moniker attack-surface evidence rather than proof of CVE-2017-8570 exploitation.
ClamAV: Xls.Malware.Emodldr-10058834-0 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Xls.Malware.Emodldr-10058834-0
\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.
Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX

RTF contains ~1066KB of hex-encoded data inside \objdata sections — may hide a payload
Suspicious extracted artifact high 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.
OLE object data medium RTF_OBJDATA

RTF contains 5 \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://schemas.microsoft.com/office/word/2003/wordml In RTF body

Extracted artifacts 5

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`objdata_00_off00002aa0.bin`	rtf-objdata-decoded	RTF \objdata at offset 0x2AA0	169518 bytes
SHA-256: `8f667d088165bd764cc4ea3b64548e42107f7b3cc7d4ce2ffcb631ed8efbc43f`
Detection ClamAV: No threats found Obfuscation or payload: likely Carved macro source contains an auto-exec entry point and execution/download terms.
`objdata_01_off0005b9c7.bin`	rtf-objdata-decoded	RTF \objdata at offset 0x5B9C7	169518 bytes
SHA-256: `b0db079eb9a86939af2721b6622710d7231b4a53e71ff88244c98ddd351c498d`
Detection ClamAV: No threats found Obfuscation or payload: likely Carved macro source contains an auto-exec entry point and execution/download terms.
`objdata_02_off000b48f0.bin`	rtf-objdata-decoded	RTF \objdata at offset 0xB48F0	169518 bytes
SHA-256: `e2aac9ce132705de0c264dc05ad29770ef279b06071445af2177335ccd132045`
Detection ClamAV: No threats found Obfuscation or payload: likely Carved macro source contains an auto-exec entry point and execution/download terms.
`objdata_03_off0010d819.bin`	rtf-objdata-decoded	RTF \objdata at offset 0x10D819	169518 bytes
SHA-256: `96c0ba595b4f567aca6f264127fadec88840555398b9f0a4f14488e6dfaad209`
Detection ClamAV: No threats found Obfuscation or payload: likely Carved macro source contains an auto-exec entry point and execution/download terms.
`objdata_04_off00166742.bin`	rtf-objdata-decoded	RTF \objdata at offset 0x166742	169518 bytes
SHA-256: `5be434f7dda363e2c0ba6c77ef8815e5329c9dc34683fb3dc398f6389e56759a`
Detection ClamAV: No threats found Obfuscation or payload: likely Carved macro source contains an auto-exec entry point and execution/download terms.

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