Malicious PDF — malware analysis report

Static analysis result for SHA-256 163256bebdc9c14c…

MALICIOUS

PDF

79.5 KB Created: 2021-07-24 11:19:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ad8bc396dcfe3a07cd5171abe85ad641 SHA-1: 4835d19f2c5d4a30b46c2542f1da30ac1aea46a0 SHA-256: 163256bebdc9c14cff0ccc55803808a1efc3ac8de0568a6c18b5faf2894d7f55
96 Risk Score

Malware Insights

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

This PDF document was flagged by an ML classifier as malicious. It contains a link farm pointing to numerous external websites, some of which are hosted on compromised CMS uploads or disposable hosting. The primary purpose appears to be directing users to external content, potentially for SEO manipulation or to host further malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://www.majbrno.cz/uploads/files/18831255561.pdf In PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/sogigenalivomos.pdfIn PDF document text
    • http://self119.net/upload/userfiles/2021/07/files/210701025427.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c1b8535c941---sutovunedesitozek.pdfIn PDF document text
    • https://winston-woodward.com/wp-content/plugins/super-forms/uploads/php/files/d84390306f004a34e690e44652b8c7d9/87389901443.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/dfjk0nsernotfjjfqpt0ifhv75/50514575961.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b63b19b9695---sonazinew.pdfIn PDF document text
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/160c353ca7c58d---68161308932.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a6178c7cabe---xulabepopibopasinofipi.pdfIn PDF document text
    • https://lacaune.hu/userfiles/file/36888624276.pdfIn PDF document text
    • http://donghozibistore.com/luutru/files/bidinagawilavodes.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/2hbg03h3l3etifuq5jmuu21mop/40457161252.pdfIn PDF document text
    • http://kaupa.cz/userfiles/file/nadulizenuzorosibevuwogu.pdfIn PDF document text
    • https://digireg.se/upload/kejobamejerunowupulo.pdfIn PDF document text
    • http://cioccolatogallucci.it/userfiles/file/pepip.pdfIn PDF document text
    • https://soportedevida.mx/ckfinder/userfiles/files/90603643988.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16072e77a82be4---rodumuba.pdfIn PDF document text
    • http://shmountaineering.co.uk/wp-content/plugins/super-forms/uploads/php/files/6omfta8kv7t7cpnfv9mcf80gp6/xuxasudodivorapumudutafav.pdfIn PDF document text
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/d776b759ded21b4afc5619c2921262c9/47454936795.pdfIn PDF document text
    • http://oumkua.com/userfiles/file/tebilixexogawi.pdfIn PDF document text
    • http://tantex.org/tantex/tantexuserfiles/file/fewufuzogepuvofosokirulug.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/447ff06e6a5d272522a2347755d90237/27067088285.pdfIn PDF document text
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/2beea5cdd8a81648394b49261c2cac50/pekiwajugikejupudavixo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=how+to+apply+online+for+ews+certificate+in+biharPDF 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_off0000d24b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD24B 17232 bytes
SHA-256: 80a8c18fc053895523c1b48fe42e20816164522f170abcd39b263dafb420109f
font_01_sfnt_off0000ff1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF1C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011733.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11733 10908 bytes
SHA-256: 5780dde43406df3d24eb1a9402864abc97ad5c5834e82502efbd307412c6efab