Malicious PDF — malware analysis report

Static analysis result for SHA-256 d43c915a1b5b6fae…

MALICIOUS

PDF

83.1 KB Created: 2021-10-04 19:03:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 40b35a3a7b116336eb2bdae0e76317a7 SHA-1: 9c6ea48ec6bc01d12c0004d82c58521054505f3f SHA-256: d43c915a1b5b6faee70801acaf69da0d86859edbaa6a0fbe8ca0ed94a35b274c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics as a link farm pointing to potentially malicious or compromised websites. The ML classifier and ClamAV also identified it as malicious, specifically a phishing trojan. While no scripts were extracted, the presence of numerous external URIs and the nature of the heuristics strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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://infrive.ru/uplcv?utm_term=z+table+left+and+right PDF link annotation
    • http://biznesfishki.ru/files/userfiles/files/97324024772.pdfIn PDF document text
    • http://ijiantu.com/filespath/files/20210922205344.pdfIn PDF document text
    • http://northcity.rs/slike/files/73954189887.pdfIn PDF document text
    • https://buzascsaba.hu/userFiles/file/17281479781.pdfIn PDF document text
    • https://askisan.com/upload/ckfinder/files/31404537796.pdfIn PDF document text
    • https://ccskin.com/geektic/files/lesalerimati.pdfIn PDF document text
    • http://master-br.ru/img/file/nibuvibowetutolowe.pdfIn PDF document text
    • https://expobar.vn/app/webroot/files/images/pages/files/bopexuxopibulimewelirasub.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/161540b9139712---xutibudedisopevozibapeni.pdfIn PDF document text
    • https://otoform.com/upload/ckfinder/files/vakupinetiwowuf.pdfIn PDF document text
    • https://rockyhotelsgroup.com/uploaded/files/faketelo.pdfIn PDF document text
    • http://badgerhillfarm.uk/67441388775.pdfIn PDF document text
    • http://thermcom.cz/userfiles/file/89927346707.pdfIn PDF document text
    • https://www.champagne-cornevin.fr/ckfinder/userfiles/files/dolefemowabirikulav.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613fa12c6a132---52768687689.pdfIn PDF document text
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615af2d75692f---97470389318.pdfIn PDF document text
    • https://tsafar.ir/basefile/tsafarir/files/nufupob.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614013744d225---sovamutije.pdfIn PDF document text
    • http://studiotecnicopinto.it/userfiles/files/30776603296.pdfIn PDF document text
    • http://okna-kurska.ru/page_edit/_samples/userfiles/files/gidusetujonevoxusopuxome.pdfIn PDF document text
    • http://aaykpn.com/uploads/editor/files/3465897347.pdfIn PDF document text
    • https://renhedc.com/uploads/files/202110030504293272.pdfIn PDF document text
    • http://vencedor.coop/images/admin/file/45653031304.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_off0000ddff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDFF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f616.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF616 10448 bytes
SHA-256: 010f499d9195a0277096764fb399b7279f67369aec5bed269c2581b192c34b99
font_02_sfnt_off00010d78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D78 19064 bytes
SHA-256: 4bfbf81fb2932002140c74601021e2fcd675f3e41d37eec974fa150884c027e8