Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7cbee9951419449…

MALICIOUS

PDF

84.6 KB Created: 2021-09-03 19:30:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: a1ce515a1b9c533a1edba48e3b4ad79b SHA-1: 262e0605524a1d3ba40d90d6f11df6ef96749705 SHA-256: b7cbee99514194491caa059e158aa1b2a0fb59a1aa2ae5f8db9726abc9f48943
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 external files on various domains, indicating a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests these links are hosted on disposable domains and likely used for SEO manipulation. The ML classifier strongly flagged this PDF as malicious, supporting the assessment that it is not benign. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://nothingbutsafetyglasses.com/userfiles/file/nilopapipukaton.pdf In PDF document text
    • http://biotop-zamosc.pl/userfiles/file/87271783277.pdfIn PDF document text
    • http://screen.by/images/file/18367785281.pdfIn PDF document text
    • http://terezmisszio.eu/files/file/76534063063.pdfIn PDF document text
    • https://hoangvan.vn/wp-content/uploads/files/velevapivoxijawomizoku.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/300a514804b589c728bc0ac13a283545/99124875027.pdfIn PDF document text
    • http://haustechnik-hagenauer.at/garorifufadesuku.pdfIn PDF document text
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/s9ljsbpsbkf7dnqg1l2pbcdsdn/89479847072.pdfIn PDF document text
    • http://tamilannuaire.com/var/www/vhosts/vps296430.ovh.net/tamilannuaire.com/images/file/63805975056.pdfIn PDF document text
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/da1e38c882dcacf8a54f520d156361d6/renedekejakufevixaba.pdfIn PDF document text
    • https://www.kadeavenue.com/wp-content/plugins/super-forms/uploads/php/files/2e69e2e9b6a2aaf94dc00f6e37cf873b/zisuferizegoloko.pdfIn PDF document text
    • https://ratco-hardware.com/Ups/files/degukewenovowezazolu.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b38e0282926---51954298021.pdfIn PDF document text
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/116b83f2c071dba4923dfefdc67e8517/vumebidet.pdfIn PDF document text
    • http://polipack.ru/content/file/wemapa.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160d67af4687e0---zegapowajoxalusis.pdfIn PDF document text
    • http://chongthamnguoc.vn/img/files/35430422334.pdfIn PDF document text
    • https://eyestech.in/wp-content/plugins/super-forms/uploads/php/files/e2gf4jioh6s4tkdeon81t0q5sl/35636725409.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=pre-experimental+research+pdfPDF link annotation
    • 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_off0000e7e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7E4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fff6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFF6 17244 bytes
SHA-256: 215da641a6e211f0e9a92e5be8c53cc46ecc6554e36578a16bb99e33423a8e92
font_02_sfnt_off00012bee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BEE 10900 bytes
SHA-256: 666014d6bbea48256c6f80ff5fc305604d78da998b91f2e440bcf508ed2c4c1f