Malicious PDF — malware analysis report

Static analysis result for SHA-256 6fb40c39d0e4cc07…

MALICIOUS

PDF

92.1 KB Created: 2021-07-22 13:02:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 66c0d9a155179434f4fc3853fa822e30 SHA-1: 6a2bc9ca374b3eaee6bf7f0929a01f28d8d45cc1 SHA-256: 6fb40c39d0e4cc0770e47bc8fdf75ccf5d4dfaaeb649e8c1df0f885bcb7d72e9
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm pointing to compromised WordPress sites, likely intended to host and distribute further malicious content. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicates a deliberate effort to obscure the true destination of the links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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 https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/3b2e9c11abf438543511494d5804410a/nomeda.pdf In PDF document text
    • https://freedomtampons.com/wp-content/plugins/super-forms/uploads/php/files/634513c57f449f78784fe18a4b29a644/mipamelabujaxagubafagu.pdfIn PDF document text
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/af48a8cadbd86f84f99f573148913f8f/89147482375.pdfIn PDF document text
    • https://prawobrzeze.info/userfiles/file/kowirafimogafonato.pdfIn PDF document text
    • http://www.retorika-zidar.si/ckfinder/ckeditor_uploaded_files/files/18829999996.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/77svn6hdorj9k7dmb0da1rk813/18313867580.pdfIn PDF document text
    • http://www.assignproject.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ffeda153ea---53540321531.pdfIn PDF document text
    • https://seataclighting.com/wp-content/plugins/super-forms/uploads/php/files/25417cecb41360e57f12d82ceca11c55/2610788182.pdfIn PDF document text
    • https://rsun.pro/admin/ckfinder/userfiles/files/81667016148.pdfIn PDF document text
    • https://chiuman-hk.com/images/file/6074093227.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160bd83a170353---gejaxajumuxabesogojirop.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607f4cf1e87a8---fuberix.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/ba7tffpa4c6de8iolfbqs8uql2/64979959698.pdfIn PDF document text
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/66a29c8229c2cf3f628fb0df79d6c7aa/dejijaturawumiwozege.pdfIn PDF document text
    • https://ethiquedevelopers.com/wp-content/plugins/super-forms/uploads/php/files/0c0b929fd750ec9a67925025343289ba/62394239393.pdfIn PDF document text
    • http://hasyo.net/files/file/64120857047.pdfIn PDF document text
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/160e0a2929fa08---mesezodof.pdfIn PDF document text
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/c68ispluk5kov2ac2r54dhhrhd/81267044663.pdfIn PDF document text
    • http://videoacceso.com/wp-content/plugins/formcraft/file-upload/server/content/files/160749a4a44703---fugerovaradu.pdfIn PDF document text
    • https://ajwatravel.com/wheelmarine/userfiles/file/xulemenopekukesorezemegox.pdfIn PDF document text
    • https://farstaslottsvik.nu/anvandarbilder/153/files/tonufutipokabibubok.pdfIn PDF document text
    • http://dorrstrechy.cz/UserFiles/File/19932886440.pdfIn PDF document text
    • http://zdravi-kromeriz.cz/files/file/lenizokigakudirogaxob.pdfIn PDF document text
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a6f6ff8e12d---47516403679.pdfIn PDF document text
    • https://btsmstlucia.com/atomicsteps/upload/userfiles/file/tuvakidakojo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=kidnap+2019+full+movie+downloadPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000102ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102FF 17520 bytes
SHA-256: 6b18efc7362bfb881cd0a9811ea2b6b653c33201836a330c618d39511417ea3d
font_01_sfnt_off0001301f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1301F 11000 bytes
SHA-256: af3e81e4992246ca96cf8ce5511063c90a603f28168ac77f2fbf2266c43fbc43
font_02_sfnt_off000149b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x149B6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1