Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d8a7fb44b4c5c7e…

MALICIOUS

PDF

81.4 KB Created: 2021-09-05 09:46:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1004879018102cba2d13015cff8750ae SHA-1: 6eaece3d431e3ed6a779f06aadcd496b82f97c0a SHA-256: 8d8a7fb44b4c5c7ed044e65b04e1ad21547c2ac3c78716980c5a99acf14d4db3
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains embedded JavaScript and a significant number of external URIs, many of which are hosted on compromised WordPress sites or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The embedded JavaScript may be used to facilitate the redirection or exploit PDF vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://garglob.ru/uplcv?utm_term=mathematik+5.klasse+arbeitsbl%C3%A4tter+zum+ausdrucken+pdf
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/8hh42l649c7dhj968rbgcofuf4/bisefu.pdf
    • https://bnbtravels.com/ckfinder/userfiles/files/99450918632.pdf
    • https://parc-hotel.info/file/tizedasixodigepizujaw.pdf
    • https://roc.mn/uploads/files/67410470789.pdf
    • http://begemot-rus.com/uploadfiles/file/2021080121410373499.pdf
    • https://socialacademy.gr/wp-content/plugins/super-forms/uploads/php/files/b7ff70af6530875f1e729e0cce64ba4f/96454889848.pdf
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/740c59a7c2a3d424e4dee8c81d3a7492/91935494604.pdf
    • http://builderall.info/userfiles/file/nelugotumavigufinon.pdf
    • http://tieuhocsongphuong.hoaiduc.edu.vn/ckfinder/userfiles/files/78985361827.pdf
    • http://kzlo.pl/fotki/fotki/file/51046239716.pdf
    • http://www.mananthavadynorbertines.org/www/js/ckfinder/userfiles/files/dujofofuximunutipawuxiv.pdf
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/160b6650063324---zenajamaxexawafuvidojel.pdf
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e060c8d1608---30626943172.pdf
    • https://dacola.com/upload/files/xinemomixalarozoga.pdf
    • https://hopadive.cz/ckfinder/userfiles/files/falilikinozo.pdf
    • http://uniradioweb.info/userfiles/files/58672459995.pdf
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/d268e11098a43460318f4fe0e6b3b4d1/32316244348.pdf
    • https://protradingindia.net/userfiles/file/74016000157.pdf
    • https://medtek.vn/storage/file/poxiv.pdf
    • https://ngoctraithaibinhduong.com/uploads/news_file/59567783147.pdf
    • http://ambulanceservice.pl/userfiles/file/negodogudexavesegoparular.pdf
    • http://phone-server.com/userfiles/file/76416424662.pdf
    • https://812423.qqtogeljackpot2.com/contents/files/jupubovakagi.pdf
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8e1c263ef8---5657940651.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_off0000d169.bin
be8c8bb88b1ae0fcd5ef083f132f2f7e21e19b55ca1c8264a8fc7b75549f10cf
pdf-font-stream PDF embedded font (sfnt) at offset 0xD169 11608 bytes
font_01_sfnt_off0000ec2b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC2B 16792 bytes
font_02_sfnt_off0001043d.bin
5581e3f82819e725cdf9259a6b57f9895aeb06f9796ead7a76ad6e4850536ce2
pdf-font-stream PDF embedded font (sfnt) at offset 0x1043D 19188 bytes