Malicious PDF — malware analysis report

Static analysis result for SHA-256 5699ec27d1092fff…

MALICIOUS

PDF

135.6 KB Created: 2021-09-04 09:06:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: f44cc2d8cd886afeacd91eda4b02a8d4 SHA-1: 58ebc006903cdd279f5d28da9d2ea6d0bc130bcc SHA-256: 5699ec27d1092fff43bea7cf52cd64b25ce9fdc3882d24f7c38b3de0e09c19ab
96 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to numerous other PDF files hosted on compromised websites, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. The ML classifier also flagged this PDF as malicious with high confidence. The primary purpose appears to be directing users to potentially malicious or SEO-abusing content through a series of indirect links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9853

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://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/0khtodaimembethcph7alhncgt/66769879711.pdf In PDF document text
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/a61e8b8c84d5621234fec3c532e83c4b/67628058259.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/tojiguloba.pdfIn PDF document text
    • https://ankaratemizlikcim.com/depo/sayfaresim/file/fojeliguzijovur.pdfIn PDF document text
    • https://rugsinc.in/UserFiles/files/favipeluzoxul.pdfIn PDF document text
    • https://progin.swiss/ckfinder/userfiles/files/vigujiwejiju.pdfIn PDF document text
    • http://polyalpan.hu/_user/file/jatix.pdfIn PDF document text
    • http://2020kellyfamilyreunion.com/clients/1/1c/1c0e63424c3b5e20a3d858f77c59864f/File/fumojazatevasikufosezif.pdfIn PDF document text
    • http://evolutionchonburi.com/userfiles/files/64478710430.pdfIn PDF document text
    • http://bananamusic.tw/uploads/files/202108220103199165.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d4fa4c744db---vibabugadujolijuxigakuwak.pdfIn PDF document text
    • https://www.litesourcenc.com/wp-content/plugins/super-forms/uploads/php/files/05794a65d6fadb5bbd3e112c4e6f85a7/61602599250.pdfIn PDF document text
    • http://h-n-s.net/userfiles/file/surakefoxofivi.pdfIn PDF document text
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16097a4c445da5---98408825336.pdfIn PDF document text
    • https://kurek-rowery.pl/user_pict/file/lakisosur.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/1610b264430735---53518647286.pdfIn PDF document text
    • http://aisef.org/uploads/userfiles/file/file/livojixusipuvolutigu.pdfIn PDF document text
    • http://abwingssuffolk2.com/uploads/files/25693667047.pdfIn PDF document text
    • http://telekommarketing.com/firme_data/files/lomufoz.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160820d57b6d4a---31677395055.pdfIn PDF document text
    • https://akamercedes.com/images/uploads/files/xagikafaseva.pdfIn PDF document text
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dbdbc192458---zukoviranovuma.pdfIn PDF document text
    • http://middlegeorgiacoinclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d6389f1c47---widajozadoxuju.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=design+of+rcc+portal+frame+pdfPDF 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://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_off0001a8c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A8C1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001c0d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C0D8 10964 bytes
SHA-256: 15085b2c20c6ae389893f0324973b53f072ac0202363596805ab1e95c8093fab
font_02_sfnt_off0001da0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1DA0F 21764 bytes
SHA-256: 45044150e6a4b9326260bcebdbc9a0a931b119cd80eee6624da8d9c9f4035dc1