Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c24accd7781656b…

MALICIOUS

PDF

94.6 KB Created: 2021-09-03 04:34:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-16
MD5: 4d8a49aa1a8e81c6a9bce73e10170194 SHA-1: 3636bfed12abc968164a22f47af8d135e8b028cb SHA-256: 5c24accd7781656b5f90b75a5f0441b1174f389eb325548033b619cbc2833048
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised or disposable domains, indicating a link farm. The ML classifier strongly flagged this PDF as malicious. The primary attack pattern involves directing users to external, potentially malicious, content through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 5

  • 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://jingchengs.com/jingchengs/ckfinder/files/20210630033858.pdf In PDF document text
    • http://williamshudson.org/clients/3/35/35bf74ce48b5c120232fd40fb4fe3e45/File/duvisesikesiw.pdfIn PDF document text
    • https://calldidocta.com/wp-content/plugins/super-forms/uploads/php/files/a38902020771cc9b8275df6a7aa36ac5/vukesokelomiwotipen.pdfIn PDF document text
    • http://mywayrtk.info/userfiles/file/88058422635.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/161270e7cab5ac---ruronudofiniravifumak.pdfIn PDF document text
    • http://microsolder.hu/userfiles/files/dofasudipevozesevafoju.pdfIn PDF document text
    • https://doctorchina168.com/upload/files/barujokatulijominalasexap.pdfIn PDF document text
    • http://secureyun.cn/uploadfile/file///2021083018573444.pdfIn PDF document text
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/b4b22b8c652dd3714c174ef7148619da/21179924850.pdfIn PDF document text
    • https://mmoxx.mn/userfiles/files/kataxilasokere.pdfIn PDF document text
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bdf636ac5bb---5427979409.pdfIn PDF document text
    • http://www.xpresswedding.com/wp-content/plugins/formcraft/file-upload/server/content/files/160892ac05f468---64606629714.pdfIn PDF document text
    • https://palezieux.com/ckfinder/userfiles/files/jevemeporokifovefu.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16094e712c633e---99214133607.pdfIn PDF document text
    • https://greyquotient.com/wp-content/plugins/super-forms/uploads/php/files/b5f29bc89b744a5a523fd00df9b4b22d/kitemarof.pdfIn PDF document text
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/892979d39d3e89513a646a2a0c6d5606/terazanejopa.pdfIn PDF document text
    • http://livestreaming.group/wp-content/plugins/super-forms/uploads/php/files/bl5rqd0vejh86qt2oopqh7cslvdcgk7i/lisedimumavetukexum.pdfIn PDF document text
    • http://www.esthemed.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160a3787ad1cdb---vovubejape.pdfIn PDF document text
    • http://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070a7a5b491f---derefubu.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1608f4e84c92b8---zefajobag.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/160be8f4a57263---88110284599.pdfIn PDF document text
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/8de5eb3c6648b5da44b8cfede06f5ead/misababekorasevok.pdfIn PDF document text
    • https://rumahbaruku.com/contents//files/rigomalelonavosolapu.pdfIn PDF document text
    • http://ikra-ekb.ru/files/fckeditor/file/towavalinubejagasi.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c3ca905b110---jopemelibazilaraki.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=derechos+humanos+fundamentales+en+colombia+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_off00010936.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10936 11128 bytes
SHA-256: 47f0d957ca25ee40604809bb89d17ba1655c3014f84aa2a14cc054f1b74d40fa
font_01_sfnt_off000122c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122C3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013ad5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13AD5 19616 bytes
SHA-256: a264500086da29aa1d53256f065f7519d9dacd5175119d39b06b64ad3373c4d2