Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3f37265bb2684a8…

MALICIOUS

PDF

76.4 KB Created: 2021-10-04 16:33:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 325767ab015adab3a1c9adb2a80b319d SHA-1: 9969d26d08577c4ee2de084bd23cfd7e01d50996 SHA-256: a3f37265bb2684a8786430825795d9a0ce142c08be9112ceef866624c81f16ca
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable domains and are structured as link farms. The ML classifier strongly indicated maliciousness, and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic confirms the suspicious nature of the links. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure points to a malicious distribution or phishing attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9827

Heuristics 4

  • 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://synerhu.ru/uplcv?utm_term=chapter+26+section+2+the+new+global+economy+answers PDF link annotation
    • http://packagingandfoodmachinary.com/userfiles/file/85605823248.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/51878640661.pdfIn PDF document text
    • https://askisan.com/upload/ckfinder/files/22501157803.pdfIn PDF document text
    • https://livermore.com/wysiwygfiles/file/ritazatusaz.pdfIn PDF document text
    • https://eltdb.com/UserFiles/files/38614891345.pdfIn PDF document text
    • https://alev.az/userfiles/file/21800044232.pdfIn PDF document text
    • https://sledovani3.gpshlidac.cz/www/userfiles/files/14577885837.pdfIn PDF document text
    • http://cy2hand.com/userfiles/68263805034.pdfIn PDF document text
    • https://kemxoi.vn/app/webroot/files/images/pages/files/riwipenexuko.pdfIn PDF document text
    • http://maternites-catholiques.org/ressource/site-image/files/71506549859.pdfIn PDF document text
    • http://noahmission.org/dataroom/file/47687383532.pdfIn PDF document text
    • https://wangwangcamp.com/uploads/files/202109110748281243.pdfIn PDF document text
    • http://daiichibus.vn/uploads/news_file/23103695560.pdfIn PDF document text
    • http://dagmare.de/userfiles/file/54555109527.pdfIn PDF document text
    • http://residenzaeden-albisola.com/userfiles/files/18740204495.pdfIn PDF document text
    • http://www.southpointinstitutehowrah.com/admin/uploads/file/rijugob.pdfIn PDF document text
    • http://zsdbiopharm.com/upload/files/22644802584.pdfIn PDF document text
    • https://spitalmoldovanoua.ro/ckfinder/userfiles/files/48368483941.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135071398f93---25207310419.pdfIn PDF document text
    • http://fsgpj.com/upfolder/e/files/20210914024738.pdfIn PDF document text
    • http://seattleteriyaki3.com/uploads/files/povidajobajapedenebufo.pdfIn PDF document text
    • http://mtcnx.com/upload/fckimagesfile/rivojugoziriroguwibati.pdfIn PDF document text
    • https://weborder.cloud/userfiles/file///falebalikikowetenepazis.pdfIn PDF document text
    • http://fotosvatba.net/userfiles/file/44110286673.pdfIn PDF document text
    • https://www.tocbirsen.org.tr/ckfinder/userfiles/files/42684454425.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16148e106e3153---jepixazokubimofaxe.pdfIn PDF document text
    • http://i-p-p-c.com/ckfinder/userfiles/files/keraxelusuj.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_off0000bef6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBEF6 18196 bytes
SHA-256: 908c581b983e27a0206df68b31ac8e122ca723f4dc053429b101484e00f78d62
font_01_sfnt_off0000eec8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEC8 11480 bytes
SHA-256: 9e70c38673584bde156aa8f28e607b99359fb077ba0dba6fe34ff7e94efe1d06
font_02_sfnt_off000109c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109C2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1