Malicious PDF — malware analysis report

Static analysis result for SHA-256 83357a433136845f…

MALICIOUS

PDF

97.4 KB Created: 2021-08-10 21:19:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 9532c53a57641a33d37a5e547bed8f88 SHA-1: e126ec6227b3bb84ebf0bc23333771d7edef6c09 SHA-256: 83357a433136845fd5b6f4880a35dd2a73566172a1480a3efded81fa22bf8db5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics as a link farm and a potential phishing or malware distribution vector. It contains numerous links, many pointing to compromised CMS upload directories, suggesting an attempt to lure users to malicious content. The ML classifier and ClamAV detection further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/1b061115c6f40e0a125dbff3ce6287b6/93740324388.pdf In PDF document text
    • http://tt-ural.su/admin/ckfinder/userfiles/files/suzemirovekanuvirexemoxoz.pdfIn PDF document text
    • https://dursunguney.com/userfiles/files/4544127666.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/16096fd3010587---lebozurenuge.pdfIn PDF document text
    • http://ceskylakros.cz/userfiles/file/61985824624.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/aha0ktndhsou5o7a7h9rk7sp86/53154127949.pdfIn PDF document text
    • https://hanomanberjaya.com/contents//files/kosuxuzibegoritogaw.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607131f4035ff---38267559495.pdfIn PDF document text
    • http://arcomproltd.com/userfiles/file/zakarixaxusa.pdfIn PDF document text
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160825a13c95c8---welut.pdfIn PDF document text
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/peluteludefoboxefiwurebun.pdfIn PDF document text
    • https://gionggiacam.com/ckfinder/userfiles/files/jedixupevu.pdfIn PDF document text
    • http://01host.ru/userfiles/files/rofuvevig.pdfIn PDF document text
    • http://pawsandtiaras.com/ckfinder/userfiles/files/87822463102.pdfIn PDF document text
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/9c052f6bde9a1703485dc21d802acb17/8810721581.pdfIn PDF document text
    • https://www.idromeccanicasrl.com/idromeccanicasrl.com/wp-content/plugins/super-forms/uploads/php/files/bd0646b08a102cb89ad9fd2a93b9caa4/24448707501.pdfIn PDF document text
    • http://aggengr.com/uploads/CMS/file/3562969085.pdfIn PDF document text
    • http://ajisushionline.com/uploads/files/72908339739.pdfIn PDF document text
    • https://segurosjdd.com/wp-content/plugins/super-forms/uploads/php/files/pv8i40u0sv95gh99843u9jtv56/gejasasawizirum.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/78ab1434d70e3a1023754cf3a71e9765/51094820080.pdfIn PDF document text
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/6be7bf5301e528f1c583ccbd85c850f1/72039523359.pdfIn PDF document text
    • http://quick-thailand.com/images/uploads/file/66320653044.pdfIn PDF document text
    • http://icloudcleaners.com/uploads/account/autoresponderfiles/guzoja.pdfIn PDF document text
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/pib9caouknmnmtha4olrnobo0a/juluvumetofonu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=atividades+5+ano+fra%C3%A7%C3%A3o+propria+impropria+e+aparentePDF 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_off000113bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012bd4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BD4 11256 bytes
SHA-256: e445b7f3a5f774299324e84553cb6ccb5fec0a7a204410664efe0a358bf1a325
font_02_sfnt_off000145dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x145DD 18192 bytes
SHA-256: 77771b5122e843a78f01b55c634d604d4f31b1fbef0e45743432447548d626f9