Malicious PDF — malware analysis report

Static analysis result for SHA-256 a244542054ca2eae…

MALICIOUS

PDF

95.8 KB Created: 2021-08-10 20:18:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: 1ddac58a5c071b49645ef585a5dd3c29 SHA-1: 89e929da29da781830d37cef0ad268d9e56e4116 SHA-256: a244542054ca2eaee03ade30692d907671ab892f47a4a3b678f81391446a70b9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of embedded URLs, many of which point to compromised websites or disposable domains, indicating a link farm designed for malicious redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. The presence of multiple external URIs and a link farm heuristic points towards an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://xn-----6kcaheblih5ab0a6afqbzoqe.xn--p1ai/ckfinder/userfiles/files/riwozafemotomixusateti.pdf In PDF document text
    • https://kimtuong.vn/isc/public/files/fckupload/file/giliwisifevaxiwiji.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160728832e8580---42387161511.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/ee82f255a2a0ef515569a7d11190bc45/40478467210.pdfIn PDF document text
    • https://boyanbolyarski.com/userfiles/file/88679398724.pdfIn PDF document text
    • https://adreshosting.com/calisma2/files/uploads/kixiwelafupefeguwexituw.pdfIn PDF document text
    • http://haiphongcontest.com/images/files/wosoxeberonavujali.pdfIn PDF document text
    • http://eperon-kochersberg.com/img_db/felupivewa.pdfIn PDF document text
    • https://gitteszoneklinik.dk/ckfinder/userfiles/files/fadezugutoromezikupobaze.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/013d66f23f3fc44f4b13d66314c1a8c3/kerupix.pdfIn PDF document text
    • http://denkobarbell.com/_upload/files/pikud.pdfIn PDF document text
    • https://inverpalmas.com/aym_image/files/pevuvusaxafamowabisilajam.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/bc269d2c54380d1f9dd89d1cbf75ee71/jibanifenen.pdfIn PDF document text
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/hidmqadlanrc1qllqgb9gl7370/7501098111.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607be0cd2dd9a---vukilepedesefilurunatelo.pdfIn PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/52298744930.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bdf90d0fefb---disagufanewoloduredez.pdfIn PDF document text
    • http://plafondchauffant.fr//img/user/file/sonewelizejoliboratat.pdfIn PDF document text
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082cc9315c24---vejipuse.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/38e61e26ac7508794cae930fa771263b/78193749527.pdfIn PDF document text
    • https://laihouston.com/wp-content/plugins/super-forms/uploads/php/files/b91b5c2c9a58a65d49bbfc602d33ad14/13640988322.pdfIn PDF document text
    • http://libron.pl/fckupload/assets/file/25854083313.pdfIn PDF document text
    • http://humboldthighclassof79.com/clients/1/19/19f040aad945c40a0acbd79abd3dc6cb/File/24555306353.pdfIn PDF document text
    • https://bladmedyczny24.pl/wp-content/plugins/super-forms/uploads/php/files/3794021939742427093aac338f84b48f/97839728149.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=reading+texts+for+pre+intermediate+students+pdfPDF 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_off000110ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110AE 17292 bytes
SHA-256: 96ab411d97fda18ff64b8282764f2af8d5e2bd418262e45bae5aaf02c531b398
font_01_sfnt_off00013dcd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13DCD 11044 bytes
SHA-256: 84d5fade378f8e814aee21c9f553463954696fd4b73e376e7b18e0fd8096216f
font_02_sfnt_off00015751.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15751 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1