Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c66c6ed248c7dae…

MALICIOUS

PDF

86.7 KB Created: 2021-06-25 21:24:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 2d5c6ff565436bbdbe28d710e42ae409 SHA-1: 4f23aeaf2db53816e2ea85a2c95318c1b61c7cc7 SHA-256: 9c66c6ed248c7dae57f2cac3ba405b669a777883d1a13bcf31887213c6be23f3
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to numerous compromised WordPress sites, indicating a likely phishing or malware distribution campaign. The ML classifier strongly flagged this PDF as malicious, and the heuristics confirm the presence of external URIs and links hosted on potentially compromised CMS upload storage. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://infrive.ru/uplcv?utm_term=round+house+limited PDF link annotation
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160ad694c508a3---59985047792.pdfIn PDF document text
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/cea50a15b14d89ac9170354f4781e383/33780549736.pdfIn PDF document text
    • https://www.simcoerecovery.net/wp-content/plugins/super-forms/uploads/php/files/65etl68uoohjg6b42j2b82geg9/rusipuxisozox.pdfIn PDF document text
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607176558b42e---pebok.pdfIn PDF document text
    • http://bhs-class1957.com/clients/35434/File/94004183655.pdfIn PDF document text
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/h7jidnpm4hqipcaieca89vtq7r/78908334598.pdfIn PDF document text
    • https://salvamontbihor.ro/app/webroot/files/userfiles/files/vizenaxoz.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/26mkdben6fj71078tq7u8bp092/94890598717.pdfIn PDF document text
    • https://www.sixteengrams.com/wp-content/plugins/super-forms/uploads/php/files/v47dev984s2bb2vdrnntnv3btp/55388933233.pdfIn PDF document text
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/bc16556e0bb265795d69b39951de1bad/74568841115.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/gifvcrr3dl9q5p6l8tad8p90o2/jexewixubogefazofuwo.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a59d4464c78---4748396167.pdfIn PDF document text
    • https://www.beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/37439fb09d9b6d1b70f242b5c0a69cfa/dabamonikuno.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/1606fdebd432b7---vapeparako.pdfIn PDF document text
    • http://www.ecostroyservis.ru/File/32176921148.pdfIn PDF document text
    • https://opuntia.eu/wp-content/plugins/super-forms/uploads/php/files/97656c7db0bcb062bb64f86655c304e7/6202944301.pdfIn PDF document text
    • http://bandenplaats.nl/cmsimages/file/75759758948.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074605fbded5---77182832672.pdfIn PDF document text
    • https://hometeamcorp.com/images/usr/jediborokuxon.pdfIn PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a6b1ed9ef4e---12376902619.pdfIn PDF document text
    • http://cocoal.com/uploads/file/lunizipedekuviged.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/qhl0q98e6ms5kaj20s913viim1/74981295217.pdfIn PDF document text
    • https://serwisnawigacji.pl/userfiles/file/83164383915.pdfIn PDF document text
    • http://anonelectronics.com/admin/fckeditor/editor/filemanager/connectors/php/upload_jpg/file/202105040829119137.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_off0000f16b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF16B 10396 bytes
SHA-256: db88a8d8e289193024dbe3656afe289658053519575055c67cfd114c8e1e4553
font_01_sfnt_off000108bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108BB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000120cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120CD 17288 bytes
SHA-256: 916f86fb1a8d529cce11edace8d2e75803eaf016fe95320197b4c1f3720591b5