Malicious PDF — malware analysis report

Static analysis result for SHA-256 d539b04fec34a1c8…

MALICIOUS

PDF

80.8 KB Created: 2021-09-17 07:30:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 559d18ec469002daa48387e37cdf5090 SHA-1: 39d5c7613c3086c14d42b36296e4e59ef8ab63ba SHA-256: d539b04fec34a1c88dec2697d84738d60e24d4ba8cc8dcb40382b2675044a713
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that point to compromised websites and disposable hosting, indicating a link farm designed to redirect users to malicious content. The ML classifier strongly flagged this PDF as malicious. While no scripts were directly extracted, the structure and URL patterns suggest an attempt to lure users to external sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 https://coretry.ru/uplcv?utm_term=watch+episodes+free PDF link annotation
    • http://jmvlpslimited.com/ci/userfiles/files/92838638999.pdfIn PDF document text
    • http://ahrestygz.com/userfiles/files/20210908_185217.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ff98d1dbd5---wunakarigebadiwexizujana.pdfIn PDF document text
    • http://eskuvotoszkanaban.hu/editor_up/68367539111.pdfIn PDF document text
    • https://indiantalentjunction.com/milan/media/gamorirefilefew.pdfIn PDF document text
    • http://enjoy.sk/editor_uploads/system/files/gepoxejugikerozo.pdfIn PDF document text
    • https://wedding-photos.cz/userfiles/file/wiwerog.pdfIn PDF document text
    • http://way-of-spirit.ru/upload/file/wibabub.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613a9c7d8853b---tiroxajuvuwejonamopa.pdfIn PDF document text
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1613226e78b40e---wiluven.pdfIn PDF document text
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/161409f98f3dd1---1180426163.pdfIn PDF document text
    • https://marosme.ro/hirek/file/zugelemewiwab.pdfIn PDF document text
    • http://graphicyazd.com/ckfinder/userfiles/files/99074193774.pdfIn PDF document text
    • http://permanentnimakeup-brno.cz/userfiles/files/35906916353.pdfIn PDF document text
    • https://yukkumpulgroup1.com/contents/files/45584825461.pdfIn PDF document text
    • https://nikolsbeauty.com/webroot/f/uploads/file/radudejitijisiwuzolewofig.pdfIn PDF document text
    • https://maggies-handmade.com/UserFiles/files/muzoxafinus.pdfIn PDF document text
    • http://eros-arena.name/eros/userfiles/file/sagesamap.pdfIn PDF document text
    • http://poptheme.cn/uploadfile/files/20210909_161735.pdfIn PDF document text
    • https://catwalkdogcome.com/editor_upload_image/file/27704085446.pdfIn PDF document text
    • http://upnbkk.com/file_media/file_image/file/legovanekakirizakut.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/c3l1qrivbgsjtu1ok3kcpr8eu3/66946277098.pdfIn PDF document text
    • 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_off0000d7cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7CC 17624 bytes
SHA-256: acfb95ea7b2e4afb52eb4cc6387c8abff9145c52c47a40a4c52bcb218061f91b
font_01_sfnt_off0001056e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1056E 10560 bytes
SHA-256: d7121446d6bbdc923b3667ca5c05c5e779b310d270ea365d31b7bf5784f992fb
font_02_sfnt_off00011db2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DB2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1