Malicious PDF — malware analysis report

Static analysis result for SHA-256 68831fb86bbc5e96…

MALICIOUS

PDF

73.4 KB Created: 2021-09-08 12:05:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 607098dadc31873ad417f3667fd11c04 SHA-1: f8ee83de576ccd4b28f773ea288cd903b2a708a5 SHA-256: 68831fb86bbc5e96ea501a6b0aa4ce7805cc42f72809a20c145c0fd078eb34e6
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs that point to compromised WordPress sites and other disposable hosting. The ML classifier strongly indicates maliciousness, and the heuristic firings suggest this PDF is a link farm designed to redirect users to potentially harmful content. No scripts were extracted, but the primary attack pattern is the distribution of malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://laborke.ru/uplcv?utm_term=ocr+pdf+using+python PDF link annotation
    • https://carpanea.it/wp-content/plugins/super-forms/uploads/php/files/0f567e832cfa15255d6dd137d7049f75/lerajarulubeperem.pdfIn PDF document text
    • http://changju-hotel.com/CKEdit/upload/files/15432485162.pdfIn PDF document text
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/457a331a4417486f8e113c43ed833387/29079674644.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/a80ffd48c9747206d21acabae589d9aa/dimonisakuj.pdfIn PDF document text
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2b7bacbf7d---jerijazakokenex.pdfIn PDF document text
    • http://goodwill.pl/userfiles/file/fifizixabok.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609cc4b34f63b---2475197828.pdfIn PDF document text
    • http://clingac.es/d/files/sakojikivobepewozatub.pdfIn PDF document text
    • http://analogsys.com/uploaded/file/1319175279608c149304e3f.pdfIn PDF document text
    • http://alphabodysupplements.com/newerac2c/userfiles/file/6597442144.pdfIn PDF document text
    • https://assistenza-termica.it/file/17978190130.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/c03c3fa005af7f2073f8824f4010a0b6/gibibulumalajurex.pdfIn PDF document text
    • http://uptindia.com/newsimages/file///73237388854.pdfIn PDF document text
    • https://allcreaturesinc.com/files/files/91213644569.pdfIn PDF document text
    • http://historia-bfured.hu/userfiles/file/kenumefi.pdfIn PDF document text
    • https://nikosdimos.gr/userfiles/file/viriri.pdfIn PDF document text
    • http://houselandia.ru/files/bamifivixoxef.pdfIn PDF document text
    • https://ubk-sad.de/azubi/userfiles/files/13723575748.pdfIn PDF document text
    • http://www.retorika-zidar.si/ckfinder/ckeditor_uploaded_files/files/47594735504.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/o7kukh9p6s40l1emgipv19k02m/gegilonewitumobukomixuv.pdfIn PDF document text
    • http://medob.org/SITE/files/editor/file/wiguxepirepugafenuvidewa.pdfIn PDF document text
    • https://assignmentmart.com/ckfinder/userfiles/files/bujawizufofawudofefadusej.pdfIn PDF document text
    • https://immobilgold.com/file/mazekexofezoxufogozar.pdfIn PDF document text
    • https://gruntbudowa.pl/files/file/33413133540.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_off0000beed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBEED 15872 bytes
SHA-256: 770bcbdbfe69ec767145c063815c4dc393c296f48a7d178dbb99f48ad3aee681
font_01_sfnt_off0000e740.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE740 10796 bytes
SHA-256: 17d8a6a673d71e45bd0f2ff427d740654bd0aebc59c2a794573258e33d8f313b
font_02_sfnt_off0000ffdf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFDF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1