Malicious PDF — malware analysis report

Static analysis result for SHA-256 428817076beac8e3…

MALICIOUS

PDF

87.4 KB Created: 2021-09-19 05:19:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: bf754275c6cdf74ed8d9235eb99e3dfc SHA-1: 4c2dd91b740fec10e45fc42f23159e4dbf1355fc SHA-256: 428817076beac8e3e8c2cffc7defb0811b5fb291b9fa4256df4106c3880be344
144 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains embedded JavaScript and numerous external links, many of which point to compromised CMS upload directories or are part of a link farm on disposable hosting. The ML classifier strongly indicates maliciousness. The presence of embedded JavaScript suggests an attempt to execute malicious code, likely to download and execute a further payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 7

  • 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.
  • 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.
  • 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://crewmak.ru/uplcv?utm_term=junior+android+developer+salary+in+canada PDF link annotation
    • http://trubaopt.ru/content/file/55708480974.pdfIn PDF document text
    • http://chi-kara.net/Upload/files/xelagabifew.pdfIn PDF document text
    • http://tumakuruvoice.com/tumkurvoice/ckeditor/ckfinder/userfiles/files/13957730846.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/o9i9batludrvkottmibs7cagb2/banukamowideje.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16137e15a6df9c---kirunonenodeketidasareder.pdfIn PDF document text
    • http://ventima.ru/userfiles/file/kotoxifezenesuz.pdfIn PDF document text
    • https://itchanoi.vn/uploads/news_file/65535085099.pdfIn PDF document text
    • http://kingsauto-bar.com/js/upload/files/65369347574.pdfIn PDF document text
    • http://appli-veolia.net/ckfinder/userfiles/files/26928286083.pdfIn PDF document text
    • http://belst.by/upload/file/30374770765.pdfIn PDF document text
    • https://www.rosebankprimary.co.za/inc/ckfinder/userfiles/files/99166865497.pdfIn PDF document text
    • http://scsychem.com/upload/files/fabap.pdfIn PDF document text
    • http://sushigonewildtogo.com/uploads/files/10625210305.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/161466fe1acecd---poxasilos.pdfIn PDF document text
    • https://valleyrentals.com/userfiles/file/nomujazo.pdfIn PDF document text
    • http://alpha-cp.com/userfiles/file/puvexib.pdfIn PDF document text
    • http://cbcom.fr/ressource/site-image/files/11007594943.pdfIn PDF document text
    • http://www.giuseppe.ru/ckfinder/userfiles/files/50713460479.pdfIn PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/auj2tg2aml1m8qt1vbe2bt8c24/lukonilexozuzab.pdfIn PDF document text
    • http://fusheng-vietnam.vn/admin/webroot/upload/image/files/fupelagejapon.pdfIn PDF document text
    • https://tarzminder.com/resimler/files/parudejowuxejamafu.pdfIn PDF document text
    • http://smalternatywa.pl/media/upload/files/1d1c4f0861fadae65f12cdc40be32f00.pdfIn PDF document text
    • http://mclarenquartz.in/ci/userfiles/files/vojabasafimilifir.pdfIn PDF document text
    • https://www.sophrologue-nimes.fr/upload/news/files/likagetusolasamaxisurit.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_off0000eddf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDDF 10680 bytes
SHA-256: dc08b06067103a21418a84d9a897f9c865cccc2555cc5b84946bbdcb6098c601
font_01_sfnt_off0001067d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1067D 18872 bytes
SHA-256: 75ca5b8a48e2c0ffa59627d586a31767005271efdecf7bce63d53098ccceea2f
font_02_sfnt_off00013817.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13817 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1