Malicious PDF — malware analysis report

Static analysis result for SHA-256 a40e523a3d0d5e07…

MALICIOUS

PDF

85.3 KB Created: 2021-09-14 02:21:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 92f2b6650039289ea27d804fa135adb6 SHA-1: cd6c06ea873b875a8f095717993776fa0325de51 SHA-256: a40e523a3d0d5e07f4c49a43f42ed273b37525ff4b231fa95e0f2e5fa645d027
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple compromised and disposable domains, suggesting an attempt to distribute further malicious content. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous external URIs indicates a pattern of redirecting users to potentially harmful sites. No scripts were extracted from this sample, but the overall structure and URL distribution are indicative of a malicious document designed for payload delivery.

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 https://mediaskills.rs/files/jonig.pdf In PDF document text
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/16134df84b0f46---13270377491.pdfIn PDF document text
    • http://80tner.netsociality.com/upload/files/51809990141.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/16133fff3bfad5---42166865789.pdfIn PDF document text
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/1613e7b35bff1b---27129050535.pdfIn PDF document text
    • https://confidence-ist.com/ckfinder/userfiles/files/68192455751.pdfIn PDF document text
    • http://vinag7furniture.com/app/webroot/files/editor_upload/files/dowekizumovil.pdfIn PDF document text
    • http://fusheng-vietnam.vn/admin/webroot/upload/image/files/wolegapipakuxaw.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/ae03a870fa4846222e2661a56e99bcf0/veridugasut.pdfIn PDF document text
    • https://unitedpetexpress.unitedreloth.com/ckfinder/userfiles/files/lemimozizojunezid.pdfIn PDF document text
    • https://heuresromantiques.com/upload/files/91648514580.pdfIn PDF document text
    • http://sissonne.hu/editor_up/kilidup.pdfIn PDF document text
    • http://telekommarketing.com/firme_data/files/5069588465.pdfIn PDF document text
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/13de867251806166576e45316684d5aa/kuwozurir.pdfIn PDF document text
    • http://mobilahomedesign.com/userfiles/files/63317772901.pdfIn PDF document text
    • https://goez3.com/10005001208290177/ckfinder/userfiles/files/ranatog.pdfIn PDF document text
    • http://the-bom.kr/upfile/files/rojopazekisabebapumej.pdfIn PDF document text
    • http://zvaracskaskola.eu/editor_uploads/system/files/jomadizovosomukamaxejebub.pdfIn PDF document text
    • https://path.mn/userfiles/files/xefazetemesetuledexarog.pdfIn PDF document text
    • https://fajanav.com/aym_image/files/48757983938.pdfIn PDF document text
    • https://weblative.com/wp-content/plugins/super-forms/uploads/php/files/v73jdllntj2meqebves6brkbd4/funotorizoro.pdfIn PDF document text
    • http://jjinline.org/file_upload/file/katoliganobabosizib.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/161342bb144446---pidudipekifokilekoset.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613478a99f607---fezezudugexoges.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=sync+contacts+between+android+phonesPDF 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_off0000e84c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE84C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001005e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1005E 17620 bytes
SHA-256: 51e4f9dfca29f32c7ee0130a465035468c7cce33b703489767eb43ff74ba6dac
font_02_sfnt_off00012e7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E7B 10980 bytes
SHA-256: a9f4661bea756baf917c2874344c6b6e2028708a3f7b4327945c77bb1587b27c