Malicious PDF — malware analysis report

Static analysis result for SHA-256 f11f08d6298d33c3…

MALICIOUS

PDF

97.2 KB Created: 2021-07-02 01:01:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 17ce6e46d7c1c7dbbc69091e82907f17 SHA-1: 13b9ea454ad8736e53c4f5c746a688bca8bc08ef SHA-256: f11f08d6298d33c39d0b44e1e9e55e9a18859dd5059f0ae68dbf76b27062f99e
196 Risk Score

Malware Insights

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

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. Static analysis revealed it functions as a link farm, containing numerous URLs pointing to compromised CMS uploads and disposable hosting. These links likely lead to further malicious content or phishing pages, indicating a multi-stage attack. No scripts were extracted, but the PDF structure itself facilitates the redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9936

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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
  • 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://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/67u66b4aqdcap8km7refd8ptsi/54390545095.pdf
    • http://stlnsk.ru/uploads/file/putibalosu.pdf
    • http://developmentassociationofnagaland.org/nbloom/fckuploads/file/16580695761.pdf
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070bae1992a3---jagopagenakinogu.pdf
    • http://beergolfers.com./blog/images/file/tezifinobagojofapogot.pdf
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/dfns51ggf6vu57tdmhsqlk8uvl/78039796464.pdf
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084b47bda5aa---paxokadutanavedamof.pdf
    • https://sammycar.ch/sammy/sites/default/sammyfiles/newsletterfile/32601933290.pdf
    • http://alicekhenrylawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/setagixosedida.pdf
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160ace36ad1b26---49203059400.pdf
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/ic5qgnemth74nn9vej6l5p6c84/5934149042.pdf
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a252aca1092---65371182614.pdf
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607d6fcd353e2---jipixukogolave.pdf
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/4489109e2c0def33ef0562c6fe9c09fd/98406261227.pdf
    • http://kmsenior.org/file/files/94471263656.pdf
    • http://lbtech.kr/upfile/files/59595454254.pdf
    • https://xn--hjrnskadeakademien-mtb.se/userfiles/file/35519704989.pdf
    • https://aliencosmicexpo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ff22e50f7f---2824676040.pdf
    • https://www.alpha-dynamics.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16082cab393ef5---98688458394.pdf
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/p7reumgbd32d85dtqo5jqh33pu/88566706461.pdf
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609800157cd0f---firikowakijuzaz.pdf
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/55bdbcc8ae3edd657eb813aba35d6571/pusomozapajokawa.pdf
    • http://whewfamily.com/clients/12004/File/bawugofudewenotelaxizaf.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=a+direct+democracy
    • http://e1pl2.nazwa.pl/busy/fotki/file/nomap.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011aa1.bin
6b65542946bf16a16325687379e7fd35618e6fcff9a434ad2b6000d70e879339
pdf-font-stream PDF embedded font (sfnt) at offset 0x11AA1 17496 bytes
font_01_sfnt_off00014892.bin
94e2cd32d2c67b4b040fd77d66ef05918fb6f475e9f6d1fc3038292b848e046a
pdf-font-stream PDF embedded font (sfnt) at offset 0x14892 10308 bytes
font_02_sfnt_off00015fd7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15FD7 16792 bytes