Malicious PDF — malware analysis report

Static analysis result for SHA-256 a0c643bab6cbf308…

MALICIOUS

PDF

71.6 KB Created: 2021-09-26 23:52:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8ec23e31165ea0259fe9209f7d4f05b0 SHA-1: 3d406d6e3c298e2294624375ae7b192d2c8f2c2d SHA-256: a0c643bab6cbf3081dd2592d2e5116ec619a9257fdaf65d22922272553c3e225
164 Risk Score

Malware Insights

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

The sample contains embedded JavaScript, a common technique for executing malicious code within PDFs. It also features a link farm pointing to multiple disposable domains and compromised WordPress uploads, suggesting an attempt to obscure the final destination and evade detection. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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://perechen-jurnalov.ru/js/ckfinder/userfiles/files/nelesolali.pdf
    • http://xn--80adpfaaeictf0c6c7i.xn--p1ai/public/file/11334849288.pdf
    • http://valencia.thepokeluau.com/uploads/files/34251726358.pdf
    • https://ontech.vn/images/ckeditor/files/94844757521.pdf
    • http://utpcomp.ru/uploads/files/betibegarukepotegaxubod.pdf
    • http://xingzhongjing.com/userfiles/file/20210907062808_1299621685.pdf
    • https://dehayemek.net/upload/ckfinder/files/fitaviletojenedejavuzuvor.pdf
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/bcd12bacc2b52c63b256c5e07346a06e/zejoneposukusina.pdf
    • http://nachhilfeschule.havonix.com/ckfinder/userfiles/files/76068399047.pdf
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/16146bc9c727a4---18773271874.pdf
    • http://aokisuper.com/ckfinder/userfiles/files/lavijigapavolexafutesunaf.pdf
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/161407e2e81331---juzevabebavobelo.pdf
    • https://ntiverification.com/userfiles/file/69547080449.pdf
    • http://allasclub.com/campannas/file/kolijiwunub.pdf
    • http://www.casasemio.com.br/ckfinder/userfiles/files/16254319164.pdf
    • https://lnpro.in/ckfinder/userfiles/files/vuvafuwimute.pdf
    • https://52fantasies.com/home/holly/public_html/ckfinder/userfiles/files/84361992431.pdf
    • http://mevlanaasm.com/resimler/files/75016836516.pdf
    • http://friulanamarmi.it/images/file/goludufelukiwolebu.pdf
    • http://quanhoangtsi.com/upload/quangtri/files/50703828463.pdf
    • https://newtech-utm.pl/userfiles/file/xijewa.pdf
    • http://azizavacanze.com/userfiles/files/vevujeburemufivezag.pdf
    • http://globalbando.com/DATA/upload/files/202109221441387234.pdf
    • https://cananalimdar.com/wp-content/plugins/super-forms/uploads/php/files/5ej8pj2ttr9dqedqgk8p8on71a/judazagifuwazujuxasu.pdf
    • http://lsbwg.com/ckfinder/userfiles/files/20210917/021505807.pdf
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/r7mhd84hnst7jg89fipf1sqj0e/jukovufibinujijafofele.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=asus+rog+phone+5+antutu+score
    • 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_off0000b676.bin
375199d33c812a2f9e4b1fe11630e2d13d3bb7f028780bcb7420d88d07fc2dd1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB676 15896 bytes
font_01_sfnt_off0000df86.bin
7ef3358bb9cd61483827fa8c4aa7c89352c63656be1d74a751befc1e2805a778
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF86 10732 bytes
font_02_sfnt_off0000f840.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF840 16792 bytes