Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8cd83605a1a7650…

MALICIOUS

PDF

86.2 KB Created: 2021-09-18 21:29:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 95db2b6c3ef9befede9592897ac820e4 SHA-1: ae1224c9b9423e1c432a3adc178964b7ac63307a SHA-256: c8cd83605a1a7650357ca7e8a5143b87c430480da876314c1087f379065c6492
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://tiga.co.th/ckfinder/userfiles/files/43340283998.pdf
    • https://locktactyuma.com/ckfinder/userfiles/files/18195092220.pdf
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/ae926d184a2c32f458bd073e764dc7bd/xilafesi.pdf
    • http://www.detskaoptika.cz/ckfinder/userfiles/files/28370481001.pdf
    • http://agataklimowska.pl/userfiles/file/ledexenosuwaxejij.pdf
    • http://tootingtaxi.com/survey/userfiles/files/zumekepolifo.pdf
    • http://murielbellhomes.com/userfiles/files/xefiwemunafaxevarusevafa.pdf
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/c90f7c796f6ddd6e3d75f2bd1c5987f2/60366352541.pdf
    • https://drproperty.in/userfiles/file/3392245734.pdf
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161310bb148f1d---37595954575.pdf
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/fitk5amops1f30gvqm8svlhabj/xanuzuxofawerix.pdf
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/16142e52076598---noruwakazugenuvutuxedelob.pdf
    • http://orourkelawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xilomajife.pdf
    • http://neonatal-surgery.ru/userfiles/files/baxoputokolawa.pdf
    • http://kkagro.com/media/images/upload/file/govikefow.pdf
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613552a14fc6d---33811484789.pdf
    • https://textmakareknutsson.se/upload/image/losirajewalenor.pdf
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/161336ebbd4227---filifutafefizowas.pdf
    • https://bocion.com/ckfinder/userfiles/files/sivaguxaj.pdf
    • http://www.ondebiz.com/userfiles/file/didekiwofu.pdf
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16142388eca133---18051744662.pdf
    • https://www.disbel.es/ckfinder/userfiles/files/92482262274.pdf
    • http://vcelari.naceradec.cz/includes/ckfinder/userfiles/files/wudopavezuzajanibaviter.pdf
    • https://majorsagilekvaros.hu/uploads/file/rofapovanukajazasobotiki.pdf
    • https://careerexpo.alljobsinliberia.com/ckfinder/userfiles/files/38287599152.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=ml+generator+apk
    • 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_off0000ed07.bin
548c34b670e00a35f4a3ceb384ed94df1d831084bda9052583f1005134749aef
pdf-font-stream PDF embedded font (sfnt) at offset 0xED07 18244 bytes
font_01_sfnt_off00011c52.bin
576d563365a84ce4c7e5f7142c1dcd03cc8e4b2510c6913477cb3642c0e8bbed
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C52 10252 bytes
font_02_sfnt_off00013386.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13386 16792 bytes