Malicious RTF — malware analysis report

Static analysis result for SHA-256 6d949dd2e60f6ad2…

MALICIOUS

RTF

2.57 MB Created: 2018-02-04 22:50:00 First seen: 2018-02-19
MD5: b127b79890f9fd09c83c24b13e7f45af SHA-1: 5913ea0b1688a77ca9bd16677414fb43e504606b SHA-256: 6d949dd2e60f6ad265b5bfcb20eb770d431e8caddd9779664ee4742342fe3355
282 Risk Score

Malware Insights

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

The RTF file contains multiple embedded OLE objects and triggers the ".objupdate" directive, indicating an attempt to activate them. The critical heuristic firing for CVE-2017-8759 confirms exploitation of this vulnerability for OLE activation. The presence of embedded shellcode and the URL pointing to a VBS file suggest that the exploit is used to download and execute a secondary payload, likely a downloader or dropper.

Heuristics 8

  • 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.
  • ClamAV: Doc.Macro.Obfuscation-6391394-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Macro.Obfuscation-6391394-0
  • \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 ~1079KB 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 10 \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://fast-cargo.com/images/file/vb/27.vbs\\ In RTF body
    • http://schemas.microsoft.com/office/word/2003/wordmlIn RTF body

Extracted artifacts 10

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00002c1b.bin rtf-objdata-decoded RTF \objdata at offset 0x2C1B 67630 bytes
SHA-256: 364fbbb789064f83851261b6e4badcd1a2f18669b011c1896617cf2a807c14b9
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript.Shell Carved macro source contains an auto-exec entry point and execution/download terms.
objdata_01_off00029ade.bin rtf-objdata-decoded RTF \objdata at offset 0x29ADE 67630 bytes
SHA-256: a5c999929c76646392e29d0d0d5b7f885de9aacebcac4b8c43a9b4c6672b4e2c
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript.Shell Carved macro source contains an auto-exec entry point and execution/download terms.
objdata_02_off00050918.bin rtf-objdata-decoded RTF \objdata at offset 0x50918 67630 bytes
SHA-256: 48e55762396b0ffa146bb1fbc08902f0d3de14540b2d4839e49541fe2f7a377b
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript.Shell Carved macro source contains an auto-exec entry point and execution/download terms.
objdata_03_off00077752.bin rtf-objdata-decoded RTF \objdata at offset 0x77752 67630 bytes
SHA-256: 675a23f884e76bc7b2fbfc05ea152863522e13666d4e711676e13a6232766f25
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript.Shell Carved macro source contains an auto-exec entry point and execution/download terms.
objdata_04_off0009e593.bin rtf-objdata-decoded RTF \objdata at offset 0x9E593 67630 bytes
SHA-256: 43259fd5d97ccd3d6070efc12a722dd4138fed9e8ee7924963361a68cf9315c3
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript.Shell Carved macro source contains an auto-exec entry point and execution/download terms.
objdata_05_off000c53cd.bin rtf-objdata-decoded RTF \objdata at offset 0xC53CD 67630 bytes
SHA-256: f10109717bad260bb5cbe912ce052f9e1466a3cb3e2de70638ab97ae0e24dee2
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript.Shell Carved macro source contains an auto-exec entry point and execution/download terms.
objdata_06_off000ec207.bin rtf-objdata-decoded RTF \objdata at offset 0xEC207 67630 bytes
SHA-256: 2b68c43dae6d21ac7bdd17e883324acb87b04046f1f0a544f0036db537fb4fcb
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript.Shell Carved macro source contains an auto-exec entry point and execution/download terms.
objdata_07_off00113041.bin rtf-objdata-decoded RTF \objdata at offset 0x113041 67630 bytes
SHA-256: 133289516a91d1216e3bd747addc6295f3fca6599c5a2c8061508b23f4e1e177
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript.Shell Carved macro source contains an auto-exec entry point and execution/download terms.
objdata_08_off00139e7b.bin rtf-objdata-decoded RTF \objdata at offset 0x139E7B 67630 bytes
SHA-256: eb3e383987740de631c46c50485164d17321dd8de3deaeb441d6987837a2f861
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript.Shell Carved macro source contains an auto-exec entry point and execution/download terms.
objdata_09_off00160cb5.bin rtf-objdata-decoded RTF \objdata at offset 0x160CB5 67630 bytes
SHA-256: b77e3c34fa89bb3c7ca8cc61b0fa376ab8fdf1cecd4d82cf24d61170e0b9b616
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript.Shell Carved macro source contains an auto-exec entry point and execution/download terms.