Malicious PDF — malware analysis report

Static analysis result for SHA-256 716463a1e7821ba7…

MALICIOUS

PDF

80.9 KB Created: 2021-09-17 21:06:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 47865fa91371cb4f4e2f89c920f043b6 SHA-1: bb9010ed15be1b7664442227a263554523cf5281 SHA-256: 716463a1e7821ba7d5c8db98621b3b9c4f39453959ef39ad1a6ad9b7ad7f12b4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file is identified as a malicious PDF by ClamAV and an ML classifier. It functions as a link farm, containing numerous URLs pointing to various domains, many of which appear to be compromised WordPress sites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for these links, suggesting an attempt to manipulate search engine rankings or distribute malicious content. No scripts were extracted, and the document body was unreadable, but the presence of multiple external links and the 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristic strongly suggest a phishing or SEO spam campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • 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.
  • 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 http://tcgardening.com/userfiles/file/2021090506540173499.pdf In PDF document text
    • https://geya99.com/ckfinder/userfiles/files/96398054743.pdfIn PDF document text
    • http://gardensyellowcab.com/admin/images/file/99254384085.pdfIn PDF document text
    • https://www.wappa.com.au/siteadmin/ckfinder/userfiles/files/zumelirus.pdfIn PDF document text
    • https://lesartsdansmonjardin.com/userfiles/file/20210905165704.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/0d14a178666c940031625c5c90e88c58/53393810564.pdfIn PDF document text
    • https://igruppe.no/ckfinder/userfiles/files/8645207704.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613e00329ded5---mukifo.pdfIn PDF document text
    • https://valleyrentals.com/userfiles/file/84692451111.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b7bbfe75a0---xadeloxuviz.pdfIn PDF document text
    • http://remont-etalon.ru/upload/files/36292888203.pdfIn PDF document text
    • https://braindevelopmentmaps-org.neurondevelopment.org/userfiles/files/begor.pdfIn PDF document text
    • http://tvtamminhphat.com/uploads/userfiles/file/fapoguxanixe.pdfIn PDF document text
    • http://steffis-strassladen.de/userfiles/file/suzogi.pdfIn PDF document text
    • https://medarbindia.org/ckfinder/userfiles/files/rufekulalez.pdfIn PDF document text
    • https://sesconbs.org.br/ckfinder/userfiles/files/daluzutirilikazi.pdfIn PDF document text
    • http://congtyvima.com/images/Download/11844239155.pdfIn PDF document text
    • http://pwmtqatar.net/userfiles/file/46723039181.pdfIn PDF document text
    • https://haidangpc.com/contents/files/9151895684.pdfIn PDF document text
    • http://www.tempshift.com/app/webroot/files/uploadimagesfile/fezowidivupavajisu.pdfIn PDF document text
    • http://naosgym.com/userfiles/files/gugulomijefowoxetuzulofe.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/af2bcghhkb43tllblirirc0799/64493971207.pdfIn PDF document text
    • http://onlinetradeshow.ir/uploads/files/dudiwigufuxiwokak.pdfIn PDF document text
    • http://96stone.ru/userfiles/file/72672914234.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=find+my+android+device+idPDF 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_off0000d74a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD74A 18056 bytes
SHA-256: bdda3ce51cae0a14c791d519827c94929d52b9f9117649c5a0fa6ca8403e3b2f
font_01_sfnt_off00010646.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10646 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E5D 10376 bytes
SHA-256: c7540f352e44d44d4d6484224d67a6def441826fe7955aa08eec500c91b90500