Malicious PDF — malware analysis report

Static analysis result for SHA-256 c3c5808fb41413f9…

MALICIOUS

PDF

74.1 KB Created: 2021-06-30 03:28:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: f12deed2d7c8d604855acb235c526a48 SHA-1: 7a135365c0019767430020697ea8b3e9c3c6e96b SHA-256: c3c5808fb41413f9a8bd1edd47a2d434e85130a93c66a526aa9e15898075395e
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file contains a large number of external links, many pointing to compromised WordPress sites. The ML classifier strongly indicates maliciousness, and the link farm structure suggests an attempt to manipulate search engine rankings or redirect users to potentially harmful content. No scripts were extracted, but the overall structure and heuristic firings point to a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://crysiq.ru/uplcv?utm_term=tabs+for+beginners PDF link annotation
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/kpifsus3n1q6ou0obgq4dnuh7d/68729233880.pdfIn PDF document text
    • https://gearforfree.com/wp-content/plugins/super-forms/uploads/php/files/n5k350jq4uucn82kkk2d4o2u2c/99197219525.pdfIn PDF document text
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/008d6a098fbda7b0c4a97ffc963e944f/93358333556.pdfIn PDF document text
    • https://iescolumbus.org/wp-content/plugins/super-forms/uploads/php/files/c427aba80be2fb23849029261693c2c8/dubofoje.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/13248nioarq3usbs256qcpms33/14771834941.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/1606cdef0f107c---28386351875.pdfIn PDF document text
    • https://adikkeempat.com/contents//files/solumelevibotop.pdfIn PDF document text
    • https://lightspec.com/wp-content/plugins/super-forms/uploads/php/files/221b47d905e7abf573ec66383b79f7de/95200082863.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/160b79e35be4fe---48022067068.pdfIn PDF document text
    • https://edoxmarketing.com/wp-content/plugins/super-forms/uploads/php/files/aak4hjhs0nklp315p6rj868hbg/bovekosotojal.pdfIn PDF document text
    • https://www.travelticket.com.au/wp-content/plugins/super-forms/uploads/php/files/kr695hefaheptb62f0kuu9nsip/dukovevutod.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607e02886e653---98722392950.pdfIn PDF document text
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/53c96a7a291e8104be9f7c7972bcdabf/73276298735.pdfIn PDF document text
    • https://agilitynd.com/wp-content/plugins/super-forms/uploads/php/files/535d4f55e493c29c58b1ed49a7403016/tutowafufedemuli.pdfIn PDF document text
    • https://www.myjamaicais.com/wp-content/plugins/super-forms/uploads/php/files/b0d3b13ffe0f559653aad8d5ba156ab6/25819750216.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/160962bbfc113f---safamipiwelopem.pdfIn PDF document text
    • http://cosmickino.ru/sadm_files/72559601667.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092e01086128---29162307119.pdfIn PDF document text
    • http://zawayakw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b04a88c03ab---rakamokugisedibibiriwigo.pdfIn PDF document text
    • http://botanicgardenscafe.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16092c2abc8087---panizaxinenog.pdfIn PDF document text
    • https://www.mysmilestudios.com/wp-content/plugins/super-forms/uploads/php/files/72a8df0bf7ba61b40221fa020c73715c/sapamezamata.pdfIn PDF document text
    • https://cordovajewelry.com/images/file/68048237446.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/3681qtk3iu37ggj45l5aaeqv16/kigadawopi.pdfIn PDF document text
    • http://www.clc-engineering.com/siteuploads/editorimg/file/63461826211.pdfIn PDF document text
    • https://soechi.com/userfiles/file/85975842131.pdfIn PDF document text
    • https://omomediacion.com/wp-content/plugins/super-forms/uploads/php/files/c2c9c7b00c121f13498d50e05a28dc41/41666195069.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_off0000c1ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1AB 16204 bytes
SHA-256: 62081545311165fb2a1d6119fc3f7e869282877f48ae2bb62afe903693018123
font_01_sfnt_off0000eba1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBA1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000103b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103B8 10348 bytes
SHA-256: 213976f92778e7a9c5eebb580b2ce24a60e82ea63fb86568b91d9914151f58d6