Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ef6df57fa64d798…

MALICIOUS

PDF

83.9 KB Created: 2021-08-20 03:08:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 9a3b2301e496c66d588c6d2b43d93d09 SHA-1: f3f22d8d557a0bdd58ce4009fbeb46f3089fc8e9 SHA-256: 4ef6df57fa64d798287fea10457437bfd9ae98a0d81f1f73c6793e3f981dad90
154 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised or disposable domains, suggesting a phishing or malware distribution scheme. The presence of external URI heuristics and link farm indicators further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9222

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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://polipack.ru/content/file/jifud.pdf In PDF document text
    • https://daluxerealty.com/wp-content/plugins/super-forms/uploads/php/files/jvrrjsa5jmkppl820rosp7fgj1/xemenanizasaxumog.pdfIn PDF document text
    • http://pvsystreports.com/wp-content/plugins/super-forms/uploads/php/files/h28hknhfip05tpbmo9bdk066e2/fikafaxatatekam.pdfIn PDF document text
    • http://icwest78.com/clients/67591/File/roxifafugakatobifovi.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160918cba92845---23844812731.pdfIn PDF document text
    • https://anjingliar2.com/contents//files/notunasul.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607d10851c4ba---jiwonuwalunow.pdfIn PDF document text
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160711ff5a0407---38460624899.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/1608e1db80ce54---85823886089.pdfIn PDF document text
    • http://systemsbiology.at/uploads/assets/file/robos.pdfIn PDF document text
    • https://rhagro.com.mx/wp-content/plugins/super-forms/uploads/php/files/e62ee9d7b770e38ca343ca714601f2b8/81499724421.pdfIn PDF document text
    • http://alnoorcity.com/userfiles/file/17787717755.pdfIn PDF document text
    • https://tagoproperties.com/ckfinder/userfiles/files/julewoka.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/227610epp0nkdjp5m46j22us0v/bedijanaposotakutuwaxu.pdfIn PDF document text
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071c9ec3c903---80713081520.pdfIn PDF document text
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/bbb112f2ea26359f9e40488265d9482b/jibivuluzarenukajiwebelu.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5d6b49c9b---12643969901.pdfIn PDF document text
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/634hstdd7cru0pa9qqec71lku4/20147529376.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/16085c513db761---6766661143.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f4fd3ec446---wodomup.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/fa5e38003361652c880e46cde18950cc/55601732503.pdfIn PDF document text
    • https://666666.vn/upload/fck/file/foboruxirojok.pdfIn PDF document text
    • https://alice-immo.com/userfiles/file/fanipenopisewotulomuz.pdfIn PDF document text
    • http://investinwielkopolska.pl/application/lib/ckfinder/userfiles/files/wujunuruwimixiramaped.pdfIn PDF document text
    • http://avandcie-energy.com/ckfinder/userfiles/files/93526235300.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=nirvana+in+fire+charactersPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000113c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113C7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012bd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BD9 16664 bytes
SHA-256: f564fa3cc6e19b118b5d0c462621b134903795b09a8efd0df56bcc903a8971e1