Malicious PDF — malware analysis report

Static analysis result for SHA-256 52cb4b5166b6b83e…

MALICIOUS

PDF

74.8 KB Created: 2021-09-05 15:46:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 443bfcf36bba85ebe4eae561457e143a SHA-1: 31d196cee2b69b5eaa0165e2b3e9150fbea712c1 SHA-256: 52cb4b5166b6b83e2d827b84c857e4ca96d9de9a2596d3c60a07a34b7dd00f27
96 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9939

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://wastran.ru/uplcv?utm_term=order+of+operations+with+fractions+worksheet+doc PDF link annotation
    • http://cosmoscm.com/contents//files/zukigomuzudigilaxotixoge.pdfIn PDF document text
    • http://locnuocvietmy.com/Images_upload/files/buwunejis.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a7b7be0e8d---7950613225.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160764b6eb1de2---xifoxid.pdfIn PDF document text
    • http://singlesync.com/userfiles/file/57883688754.pdfIn PDF document text
    • https://outsourcedbackoffice.co.uk/wp-content/plugins/super-forms/uploads/php/files/c6ccfe7214ef828ea7ba7d620ffadbde/sebegofegabijimobaf.pdfIn PDF document text
    • https://leganordavigliana.it/uploads/file/jegopezejuzowulunelik.pdfIn PDF document text
    • https://avgdesign.com/userfiles/file/29274811481.pdfIn PDF document text
    • http://goodslib.com/userfiles/files/mogefa.pdfIn PDF document text
    • http://getwealthythisyear.com/ckfinder/userfiles/files/77965284684.pdfIn PDF document text
    • https://harmony-lazienka.pl/Upload/file/35858548153.pdfIn PDF document text
    • http://dexgerm.com/data/file/userfiles/files/xemeziladefepelavo.pdfIn PDF document text
    • http://yogasol.cz/ckfinder/userfiles/files/58760099731.pdfIn PDF document text
    • https://cecprint.com/images/file/79541640597.pdfIn PDF document text
    • https://www.northernillumination.com/wp-content/plugins/super-forms/uploads/php/files/fe5fd3a5aa105833005bf318f96295fc/dejewozipuxexufuvosigumol.pdfIn PDF document text
    • https://abofahed.com/userfiles/file/98434765637.pdfIn PDF document text
    • https://pcetravel.com/files/file/67112406060.pdfIn PDF document text
    • https://justbuymeds.net/userfiles/file/sozaze.pdfIn PDF document text
    • http://smart.sut.ac.th/tsme/src/lib/ckfinder/userfiles/files/22023408751.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1606c95baddcf6---47318353923.pdfIn PDF document text
    • https://www.hotelamoha.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608143227f079---kalilajorabeluwopik.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a95a1140b95---49183048116.pdfIn PDF document text
    • http://tchid.net/userfiles/file/89716523689.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ai0n1b5d93b1p16mqnev8fnvf3/wowuwedulegoludixejumi.pdfIn PDF document text
    • http://pokorny-podlahy.cz/UserFiles/File/19112782984.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083b0de815f2---tidelafefugojepafepi.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_off0000c1dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1DD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d9f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9F4 10876 bytes
SHA-256: 016563724529a0b2e5afc85554d5d66ebfa5727939b26dc9226aaaf2b7a83693
font_02_sfnt_off0000f318.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF318 16368 bytes
SHA-256: 5ddad9d6067178c0be505a26697c79485c6c7d7feffd70b2fed8f80c438bf927