Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b15becfeaf141ad…

MALICIOUS

PDF

88.7 KB Created: 2021-09-13 05:51:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: a32b36f25e60f37f80378c21697880e7 SHA-1: a28b7b550ca1dfdede58811fe2151fdd729ac4fd SHA-256: 4b15becfeaf141add3974edcf77706dce3e7de72eceffa83fb51ae802de9c611
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains embedded JavaScript and a high number of external links, many of which are algorithmically generated and hosted on disposable domains, indicating a phishing or malware distribution attempt. The PDF_RANDOM_URL_LINK heuristic specifically points to a suspicious URL, likely part of a chain to deliver a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://huntic.ru/uplcv?utm_term=watch+movies+online+2017 PDF link annotation
    • http://areawifi.com/DESARROLLO/userfiles/files/xesovatepezatun.pdfIn PDF document text
    • https://granitabrasive.hu/editor_up/vogakut.pdfIn PDF document text
    • https://adeptos.clevercloud.pt/images/items/files/zubuloro.pdfIn PDF document text
    • http://teplo76.ru/uploads/file/11164154576.pdfIn PDF document text
    • http://xn--9i1b14lwsg1seumdzsx.com/upload/fckeditor/file/guvemewamuxe.pdfIn PDF document text
    • http://www.ishvani.com/www/js/ckfinder/userfiles/files/41042488516.pdfIn PDF document text
    • http://tobn56.com/UpFiles/file/43290166092.pdfIn PDF document text
    • http://media-production.net/admin/ckfinder/userfiles/files/56456992856.pdfIn PDF document text
    • http://tecs4.com/intranet/ckfinder/userfiles/files/jipabapukuwizuvegiti.pdfIn PDF document text
    • http://ambulatorioveterinariovianello.eu/userfiles/files/fixugekevotagegodobeb.pdfIn PDF document text
    • https://businessincasey.com.au/application/third_party/ckfinder/userfiles/files/13613593103.pdfIn PDF document text
    • https://creativitagh.com/pevron/www/img/file/xarumamezesapopa.pdfIn PDF document text
    • http://chochosanencino.com/uploads/files/fevuz.pdfIn PDF document text
    • http://lovec.bg/root/ckfinder/userfiles/files/14463735859.pdfIn PDF document text
    • http://xaydunghoangthanh.com/img_duhoc/files/55497168422.pdfIn PDF document text
    • http://www.emporiocaritaspisa.it/wordpress/wp-content/plugins/formcraft/file-upload/server/content/files/161387bdb236a8---22272036891.pdfIn PDF document text
    • http://zjqzzx.com/uploadfile/file/2021090412373473499.pdfIn PDF document text
    • http://vuatoyen.com/uploads/userfiles/file/70839762854.pdfIn PDF document text
    • https://namdolove.com/FileData/ckfinder/files/20210911_C8CFCD8E7FB1C3E2.pdfIn PDF document text
    • https://funbugs.ie/files/file/pumebejimibev.pdfIn PDF document text
    • https://oglethorpeclub.org/~oglethor/UserFiles/file/zemugaxegutumaxu.pdfIn PDF document text
    • http://kennycojewelry.com/userfiles/files/202109/1630495316.pdfIn PDF document text
    • https://magicdiscoradio.com/userfiles/file/53032633206.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_off0000f72f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF72F 10796 bytes
SHA-256: 5b7c49edc6d9794e3c614f4cbba6161a4171be7dad47a562c159f9e6b15b31d1
font_01_sfnt_off00011011.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11011 17808 bytes
SHA-256: 6540adf109f15c2d3eb74fcf3050bffddafb9383cddfe4bb5b0a66ad762fb8e5
font_02_sfnt_off00013d90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D90 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1