Malicious PDF — malware analysis report

Static analysis result for SHA-256 1687d4926160aee4…

MALICIOUS

PDF

70.5 KB Created: 2021-09-14 18:11:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 2f2defa5847a7710c64ac4344644b8bb SHA-1: c8a8c85ec810495d767ba21b7a4f8a0794b35c5c SHA-256: 1687d4926160aee4d8f4939a8e86af1e8ef701a44c08201b04faedadea6610ab
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to potentially compromised websites or disposable hosting, suggesting a link farm designed to redirect users. The ML classifier strongly indicated maliciousness, and the presence of multiple external URIs and link farm heuristics supports this. The document body is heavily obfuscated and unreadable, providing no direct clues to its intent beyond what is inferred from the URL structures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://irlanc.ru/uplcv?utm_term=need+for+racing+new+speed+car+mod+apk PDF link annotation
    • http://cascad-trans.ru/files/68927634895.pdfIn PDF document text
    • http://nineslash.com/user_file/file/xasodakefujobuzusaronukik.pdfIn PDF document text
    • http://tienphat.vn/imagesflashupload/file/bezivuwim.pdfIn PDF document text
    • https://pakianco.ir/data/image/uploads/news/files/15265027405.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/161339f8d87ae9---kepokirejezowubexi.pdfIn PDF document text
    • http://epoptavky.com/is/images/FCKeditor/File/wixotokovitozolusakib.pdfIn PDF document text
    • https://www.savininkai.lt/ckfinder/userfiles/files/11132278938.pdfIn PDF document text
    • https://mmeasar.com/mmeasarfiles/file/surifived.pdfIn PDF document text
    • http://viettruss.com/upload/file/47172128823.pdfIn PDF document text
    • http://coinproject.com/userfiles/image/file/gugamilipafan.pdfIn PDF document text
    • http://qdxqw.com/uploadfile/file/wemibawutaxetokulidokoja.pdfIn PDF document text
    • http://jayeonrak.com/upfile_editor/2021/files/33871392713.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f7e191a8bd---77169224580.pdfIn PDF document text
    • https://nayyaralidada.net/alpha/ckfinder/userfiles/files/gubiwor.pdfIn PDF document text
    • http://chamdure.com/DATA/files/93606723914.pdfIn PDF document text
    • http://constantemail.com/userfiles/file/1631521774vodufu.pdfIn PDF document text
    • https://dreamscapes.ca/dream_scapes/userfiles/files/sazep.pdfIn PDF document text
    • http://togclick.com/media/userFckfiles/file/44407739594.pdfIn PDF document text
    • http://schokoladenbrunnen.de/idata/8154685562.pdfIn PDF document text
    • https://www.esfa.bg/root/ckfinder/userfiles/files/96160701457.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/f21132580da8c4a9e96a0e4a4eec297e/makaline.pdfIn PDF document text
    • https://heyratacademy.ir/file/dubipa.pdfIn PDF document text
    • https://peltonfell.org.uk/ckfinder/userfiles/files/26141569858.pdfIn PDF document text
    • http://kernenshepler.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/pumiwazotunemuv.pdfIn PDF document text
    • http://aolisenjiancai.com/data/files/5297085387.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_off0000b2e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2E0 15856 bytes
SHA-256: 8ae09410fa00820872b3a25c2b5cd6949f931bbad5de7eb8c51b0b1da22af5f9
font_01_sfnt_off0000db17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB17 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f32e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF32E 10976 bytes
SHA-256: 0edd6d57b5256a15b5aed1dfeb5e9a4dd4d0383ab6f781c0729f5697963d864e