Malicious PDF — malware analysis report

Static analysis result for SHA-256 c36b8a2b3639801d…

MALICIOUS

PDF

70.2 KB Created: 2021-09-24 13:26:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 3f65d40620264c8b0398efa2d5123d5b SHA-1: 10a71cece095bd0bb6620ec5ae5c9a4b510b4476 SHA-256: c36b8a2b3639801d417ca4f061d06095847a723666adfe7e6f6dfcb53dd30d2a
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable domains, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent behind the link distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://oniceh.ru/uplcv?utm_term=apple+vs+android+security PDF link annotation
    • http://tianlanip.com/filespath/files/20210914114614.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614560b4664ae---fenoz.pdfIn PDF document text
    • http://tataservice.it/userfiles/file/surabisoraju.pdfIn PDF document text
    • http://boletos.luzservicos.com/ckfinder/userfiles/files/xifisakapuzononudemo.pdfIn PDF document text
    • https://www.uflo.edu.ar/ckfinder/archivos/documentos/28198846964.pdfIn PDF document text
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614341894bbd6---joloroduzusiturejok.pdfIn PDF document text
    • http://k3projekt.pl/uploads/userfiles/files/bupupukumi.pdfIn PDF document text
    • https://b2cexpressdemo.com/userfiles/file/dogijilijopexep.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/91481211838.pdfIn PDF document text
    • http://npas.ru/pic/file/letujosadalo.pdfIn PDF document text
    • https://hoakhanh.vn/uploads/image/files/moteletuwabikamub.pdfIn PDF document text
    • http://zjleiou.com/images/upload/File/dodakududizodorito.pdfIn PDF document text
    • http://fujieshubao.com/zk/UploadFile/file/2021092217031173499.pdfIn PDF document text
    • http://zamaro.cz/images/fcke_files/file/82975738720.pdfIn PDF document text
    • http://iltorg.ru/upload/file/rilosunenerulolasolizixir.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16134e7a695037---80227595764.pdfIn PDF document text
    • https://myhoorayhealth.com/wp-content/plugins/super-forms/uploads/php/files/553f286887cf21aa02585e6845674eb3/teliwinuvoluragibibumit.pdfIn PDF document text
    • https://psfund.org/public/uploads/files/cms_files/49980824126.pdfIn PDF document text
    • http://lica-mpt.it/userfiles/files/gekanobo.pdfIn PDF document text
    • https://krzczonowice.pl/gfx/file/wigaforonexufurij.pdfIn PDF document text
    • https://idosekotthonaveresegyhaz.hu/files/files/gujapozobefimivoxivitis.pdfIn PDF document text
    • http://studiotecnicoforace.eu/userfiles/files/rumojidu.pdfIn PDF document text
    • https://eprobatdz.com/ckfinder/userfiles/files/61704336722.pdfIn PDF document text
    • http://metrominicabs.com/survey/userfiles/files/41077769933.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_off0000b29b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB29B 10768 bytes
SHA-256: e7875737b9fd4076da248f305be0cffba3db8a983f342c9c9aa4085cb7f2a071
font_01_sfnt_off0000cb9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB9A 15556 bytes
SHA-256: 3c3abbf7f26dcdb18956267d540fa3d68fe5958d0d5d444920e2ccb517b68400
font_02_sfnt_off0000f328.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF328 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1