Malicious PDF — malware analysis report

Static analysis result for SHA-256 f99eefd60d4b8a43…

MALICIOUS

PDF

79.5 KB Created: 2021-10-20 19:02:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 0f55f709e72c1b40a978a4acad3a2375 SHA-1: fad0190d6bd64835faa3c690f3c9fbeeaa1b1f80 SHA-256: f99eefd60d4b8a43105c713e9adaed6418a7654733e14e305b2109a862b3b41a
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs, many of which are hosted on disposable domains and appear to be part of a link farm. One prominent URL, 'https://coretry.ru/uplcv?utm_term=singapore+airlines+data+breach', suggests a lure related to a data breach. The ML classifier strongly flagged this PDF as malicious, indicating a high probability of malicious intent. No scripts were extracted, but the sheer volume of suspicious URLs points to a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://coretry.ru/uplcv?utm_term=singapore+airlines+data+breach PDF link annotation
    • http://vattucongtrinh.com/userfiles/file/gosogurejebivililurokifa.pdfIn PDF document text
    • http://ruihuitax.com/files/file/danuvunabo.pdfIn PDF document text
    • https://equalitas.es/userfiles/file/varotopopaxaxevav.pdfIn PDF document text
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1616b0b5767fc5---27040761948.pdfIn PDF document text
    • https://jvlegacyhomerepairsmd.com/nbloom/fckuploads/file/11070595108.pdfIn PDF document text
    • https://satellietgroep.nl/userfiles/files/gadago.pdfIn PDF document text
    • https://apoiotelecom.com/imagens/img_fckeditor/file/zebulexabozukupewu.pdfIn PDF document text
    • https://ural-aiti.ru/admin/ckfinder/userfiles/files/80847718195.pdfIn PDF document text
    • http://china-hold.com/UploadFile/file/20211017211633384.pdfIn PDF document text
    • http://mini-garden.ru/userfiles/file/6002268776.pdfIn PDF document text
    • http://janjoling.com/public/ckfinder/userfiles/files/livizonujepaxo.pdfIn PDF document text
    • http://kolaykanal.com/userfiles/files/52324967633.pdfIn PDF document text
    • http://chrisdepanneservices.com/Sites/cds/files/xarobumafebasejaki.pdfIn PDF document text
    • http://ansing.nl/userfiles/file/fupufiri.pdfIn PDF document text
    • https://phuketwebstudio.com/ckfinder/userfiles/files/7537847779.pdfIn PDF document text
    • https://fentesmakina.com/paket/upload/files/61894770005.pdfIn PDF document text
    • http://deccanquest.com/konadnew/userfiles/file/dudozijagerovelofadasi.pdfIn PDF document text
    • http://kompassztuki.pl/Image/files/3365481640.pdfIn PDF document text
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/2925dcf1cb88350af0af056defff1f95/95182485290.pdfIn PDF document text
    • http://coffee33.ru/archive/file/jadus.pdfIn PDF document text
    • https://ms01bet.com/contents/files/xenetujixuxi.pdfIn PDF document text
    • http://ysenb.kr/board/file/editor/file/79299220559.pdfIn PDF document text
    • http://dlugopis.kbo.pl/ckfinder/userfiles/files/todeki.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_off0000cf85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF85 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e797.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE797 18236 bytes
SHA-256: 6b80f98f61095ca5ad8955b696f57a7a79df7c0c0eec282315e2b30c6cf83dc9
font_02_sfnt_off00011719.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11719 11008 bytes
SHA-256: 65192b00065ffd1a215698869355787f12a46f040456075adfb58b9f7b149f4b