Malicious PDF — malware analysis report

Static analysis result for SHA-256 13629b28c69e486f…

MALICIOUS

PDF

89.4 KB Created: 2021-08-10 06:18:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 73f0820dee10412dbf4dfeaa475e8727 SHA-1: 3c1792f9dfd36f197374b6bd7fb74425ac2653a9 SHA-256: 13629b28c69e486f4843ee7a2f943630ed8f3906cede1e545b706cdb8dc2626b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is a PDF containing embedded JavaScript, which is a common technique for delivering malicious content. Heuristics indicate the PDF acts as a link farm, pointing to multiple compromised WordPress sites. These sites host further PDF files, suggesting a multi-stage attack or a phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a047a4653d0---73810317840.pdf In PDF document text
    • http://maduraicaterers.com/app/webroot/js/ckfinder/userfiles/files/60409285533.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609e9ec60766d---kijodariz.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607c69676750d---juwitepedizonadakakutuwi.pdfIn PDF document text
    • http://thingsantiquesla.com/userfiles/files/4483549219.pdfIn PDF document text
    • https://gradeagroup.com/wp-content/plugins/super-forms/uploads/php/files/l97tolmjra0belkc6e44hoj3c3/50568356147.pdfIn PDF document text
    • http://happyland-nsk.net/ckfinder/userfiles/files/pugixojabakavinej.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c5590e4994f---19922375358.pdfIn PDF document text
    • http://naturallabs.fr/userfiles/file/41234268977.pdfIn PDF document text
    • https://gangwontaxi.com/FileData/ckfinder/files/20210809_6DC142F22EE4780D.pdfIn PDF document text
    • https://cornerstonelaw.eu/userfiles//file/xoxixak.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/0eho37j23mq24vpkfo0ruu9571/rodokowepefigefakuzopoli.pdfIn PDF document text
    • https://alkalacarservice.com/public_html/userfiles/file/88771567958.pdfIn PDF document text
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c67d15a117b---1116852042.pdfIn PDF document text
    • https://catwalkdogcome.com/editor_upload_image/file/nexoti.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/e1lfre5ta71b9fm5e99rjtrs6k/xivumuzapuriverelid.pdfIn PDF document text
    • http://allamericannursing.com/userfiles/file/65240005927.pdfIn PDF document text
    • https://essaidafm.com/uploads/FCK_files/file/fabazuwuxagigikigipuzu.pdfIn PDF document text
    • http://fashioncenterpoint.com/wp-content/plugins/super-forms/uploads/php/files/4065667925eb2dc330abdc053564333a/47169038083.pdfIn PDF document text
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b35594237e7---35691976297.pdfIn PDF document text
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096560ed8adc---wosekatorekidefexelaf.pdfIn PDF document text
    • https://www.vedaaz.com/wp-content/plugins/super-forms/uploads/php/files/a788847732edb2e174859f3a7dece773/migegasaxosaki.pdfIn PDF document text
    • http://clubsahdianagalati.ro/upload/editor/file/sufurajiromajonexobumifa.pdfIn PDF document text
    • http://qunjl.com/userfiles/files/23214605558.pdfIn PDF document text
    • http://shihtzufurbabies.net/clients/d/d3/d383cf0c90cf2d2391705d5438694b4c/File/59173105963.pdfIn PDF document text
    • https://prana.video/wp-content/plugins/super-forms/uploads/php/files/eg07l424sj60goblbdbod9jnf2/figukoxitigudakiguzikuges.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=why+is+my+delonghi+nespresso+machine+leakingPDF 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_off0000f82a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF82A 11060 bytes
SHA-256: 69313c5feab82b932b7a5ef7cd2f978c1c17666deab54e5ae20b11fbac31377c
font_01_sfnt_off00011183.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11183 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012995.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12995 17752 bytes
SHA-256: 44374250527b44f00651ce4acb3c4e728cd50de912c1722ee101bd69db32cf64