Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc16845a1e915f6d…

MALICIOUS

PDF

84.2 KB Created: 2021-07-13 19:47:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 787ca0581df1fea8ff80feb2fa4986fd SHA-1: 0f29b92f6231fb736661b37107dfb810d4a36c32 SHA-256: bc16845a1e915f6d5186fa34cf58bedebe82cb9d8653bcb2b287a2f908c9c13b
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm pointing to numerous compromised websites, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. The ML classifier also flagged this PDF as malicious with high confidence. The embedded URLs are likely used to redirect users to malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://tincorner.vn/uploads/files/nexiberapapimiwuguxu.pdf In PDF document text
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d2db40c3a2---67243295512.pdfIn PDF document text
    • https://www.heracles-hotel.eu/wp-content/plugins/super-forms/uploads/php/files/9l8ard9vvai8729jq3mle3tb69/repolavelulapiku.pdfIn PDF document text
    • http://lyonsmcafeereunion.com/clients/a/ab/ab8eb7fa8d7cf94b91f67e7e346c80ed/File/98911800856.pdfIn PDF document text
    • http://benardoutlite.com/admin/fckeditor/fckdata/file/27995348155.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/uchda8uvqaub8nm3b4lc26eq9v/daditiwabolux.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/dnhclteugfoo060v6rvllnknlu/7826546047.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c4d3f68ff4f---nutipulavukulenifasixetof.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac3a3377af2---newikakepojubepowobo.pdfIn PDF document text
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/ac20c133ff11b2721a620fd2f8cf0565/52138820554.pdfIn PDF document text
    • https://granchefpremiumfood.it/file/20096160346.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1609bee8727309---peminetinibekurata.pdfIn PDF document text
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608ad0f0dda0d---57648819292.pdfIn PDF document text
    • http://donghozibistore.com/luutru/files/57487554297.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/caed4ee8d33e35540239583241b5310e/katisazurisixevemipufiguj.pdfIn PDF document text
    • https://www.alphaveneers.com/wp-content/plugins/super-forms/uploads/php/files/fdb85ce410ebfcbee3a5eff11b6eeba0/72647315994.pdfIn PDF document text
    • https://seeandhearbetter.ie/img/shop//contents/72723722218.pdfIn PDF document text
    • http://dom-2000.ru/ckfinder/userfiles/files/purenuzilo.pdfIn PDF document text
    • http://project-st.ru/userfiles/file/84450275622.pdfIn PDF document text
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/061ah2cleqil3kscdkoah744j7/supozol.pdfIn PDF document text
    • http://oguzlarotomatiksanziman.com/depo/sayfaresim/file/31007074489.pdfIn PDF document text
    • https://vico-domrep.com/ckfinder/userfiles/files/wezebikeroluketasivig.pdfIn PDF document text
    • http://ainut.fi/userfiles/file/78502389896.pdfIn PDF document text
    • https://shared401k.com/wp-content/plugins/super-forms/uploads/php/files/65af88e32c1971eddc3b3c9ae6791a82/gutirakunamebujoxebidifim.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/4201ab67369a40ddfee3337561ac4271/9862795636.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=periodic+table+colored+metals+nonmetals+metalloidsPDF 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_off0000e72c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE72C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ff3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF3E 16744 bytes
SHA-256: e568e7a020dfb176464baef684e4c0afb892fec1f3736ffe3f098bf6ef37f7da
font_02_sfnt_off00012aac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AAC 10672 bytes
SHA-256: 4f7af1fabcc2eebb1efc48bdf882bb51819fb03bf4238f909aaf305337e8b9ed