Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf75cc5eff11b73a…

MALICIOUS

PDF

94.3 KB Created: 2021-08-14 01:08:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 74d2cc0d0e687e67426bc30e903d3012 SHA-1: da4a6f3bc0400269f7eeb649c9b659819dd5cf96 SHA-256: cf75cc5eff11b73a5349f2421b3a18404c845e56024ff8d0cff4bb0a79b7e4d4
96 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised WordPress sites, indicating a link farm designed to redirect users to malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious link farm. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 5

  • 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://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/1025685b964707942078b1f2b0aab45d/58045632820.pdf In PDF document text
    • https://cremyco.com/app/webroot/docs/file/fageribow.pdfIn PDF document text
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/pas9vticlnkln9vkcf2o9onvbu/44053039802.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/jjtus3i005iajmbkogc1udtna9/leridofoji.pdfIn PDF document text
    • http://zonwering-belgie.eu/ckfinder/userfiles/files/40023231989.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f29e1a2096---xegirekivuzabelozesomap.pdfIn PDF document text
    • http://studiovalentini.eu/userfiles/files/xitom.pdfIn PDF document text
    • https://brigitte-farner.ch/userfiles/files/puripaxaxobu.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abcddbe7d63---xepanisapegumitamari.pdfIn PDF document text
    • https://ghnservizi.com/file/musanikejubipobogak.pdfIn PDF document text
    • http://micruts.org/userfiles/file/45013909058.pdfIn PDF document text
    • http://ahdongjiu.com/upload_fck/file/2021-4-29/20210429170835613542.pdfIn PDF document text
    • https://argumentua.com/i/file/newaladinexes.pdfIn PDF document text
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/4775a5455d660854347e43c0d2795cec/92242499640.pdfIn PDF document text
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/3485698fbd97bb48c3b39ae0913f1989/dotojolomin.pdfIn PDF document text
    • http://fontanarosaserigrafia.it/userfiles/file/kixerix.pdfIn PDF document text
    • http://proxima-design.cz/files/file/gorusifugudenezep.pdfIn PDF document text
    • http://mtsp.by/userfiles/files/kagopuvox.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/0db5ad6476b705a374d2dde1fea879d5/82252912604.pdfIn PDF document text
    • http://www.cafeinca.com/img/public/contenido/file/69939778743.pdfIn PDF document text
    • https://www.autopsrus.com/ckfinder/userfiles/files/nofopiresalolixuta.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a9728237815---47676955727.pdfIn PDF document text
    • http://doks-films.com/pcms/content/file/zavof.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=solving+rubik%27s+cube+fast+videoPDF 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_off00010be9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BE9 16724 bytes
SHA-256: d380d72f6c35e73a057cd5c9c582a6937ad7b900f069d141d2489116c9f81cb0
font_01_sfnt_off0001374b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1374B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014f62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14F62 11156 bytes
SHA-256: cc5549d09210a03da1b0b462ad99c23577e2aba68365cb3fee84a812da9188c4