Malicious PDF — malware analysis report

Static analysis result for SHA-256 8535df547a048707…

MALICIOUS

PDF

68.3 KB Created: 2021-09-04 07:35:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 96b977b356b158b5fe6a8ce4c545a372 SHA-1: b0a92d018081dac8630917d90968e0c9bc085fc4 SHA-256: 8535df547a04870761288b2498109858400b22bf5be05ea533c42ecd48129abd
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to redirect users to phishing or malware distribution sites. The embedded JavaScript is likely used to facilitate these redirects or exploit PDF vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://wastran.ru/uplcv?utm_term=digital+marketing+skills+pdf PDF link annotation
    • http://signauction.net/userfiles/file/76981718371.pdfIn PDF document text
    • https://aparcaderoshaddaichile.cl/uploads/images/files/82864868008.pdfIn PDF document text
    • http://extintoresorigen.com/images/editor/35917080933.pdfIn PDF document text
    • http://toyotaprius-custom.com/js/upload/files/78977455368.pdfIn PDF document text
    • https://vdbergelectro.nl/wp-content/plugins/super-forms/uploads/php/files/94aac73b585eb8f97b63c671d7e6f50b/63405136882.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a1aa30d9e50---kegusijak.pdfIn PDF document text
    • http://latexindia.com/userfiles/file/begozuzek.pdfIn PDF document text
    • http://biaikatolikus.hu/files/file/52168962675.pdfIn PDF document text
    • http://szao-spb.ru/images/news/file/gedona.pdfIn PDF document text
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/v402vti51ld9iha2f4eucb84lc/wijewubaxatomebuv.pdfIn PDF document text
    • https://romalasergroup.com/userfiles/files/mawofamudemufidalozav.pdfIn PDF document text
    • http://hainescentreasia.com/images/file/lonemonatatokananigutodor.pdfIn PDF document text
    • http://toicodonlyson.com/uploads/files/gizujerevafomezurovad.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160db13587d3d4---gejatekixitimonarux.pdfIn PDF document text
    • http://villa-margherita.biz/userfiles/files/37926767856.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/1coa9g8fafp2qfq03uu5n5tns0/ludaludagomela.pdfIn PDF document text
    • http://jiin-torng.com/uploadfiles/20210722132604.pdfIn PDF document text
    • http://brenna-ski.pl/userfiles/file/77221575271.pdfIn PDF document text
    • http://drapikowski.pl/uploaded/fck_files/file/35937082900.pdfIn PDF document text
    • https://anfauglir.com/images/file/mewifepetuvuwavipimek.pdfIn PDF document text
    • https://envomask.com/wp-content/plugins/super-forms/uploads/php/files/4c025837a7f7434a3ad609b7273055cf/71145584368.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_off0000afba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFBA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c7cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7CC 14388 bytes
SHA-256: d64725137fb505f06ad4a5ea64457687fb5571ed919519d1b90abc1cad27d1b7
font_02_sfnt_off0000eb8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB8C 10812 bytes
SHA-256: f59da059d8b1da89df1434af00ebae912fdcd40bd6f5edb56ec094c52db34d12