Malicious PDF — malware analysis report

Static analysis result for SHA-256 b73c4b8339a1028d…

MALICIOUS

PDF

74.2 KB Created: 2021-09-01 10:27:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 09f720f64385e297f3b053242ea039f5 SHA-1: 38b2c8d9e0a05328b07eb7556f9d7c3f7f15f06b SHA-256: b73c4b8339a1028dcf50d59e990c1305a064787d1245bca021a405f075822895
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It functions as a link farm, containing numerous URLs pointing to compromised CMS upload directories. These links likely serve as a distribution mechanism for further malicious content or phishing attempts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 http://remproekt-m.ru/admin/ckfinder/userfiles/files/56495501280.pdf In PDF document text
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/160836150bb45f---49344790668.pdfIn PDF document text
    • http://www.orhancoskun.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fdf342641f4---safogipisuro.pdfIn PDF document text
    • https://ptkas.com/kingkong/userfiles/files/40745668913.pdfIn PDF document text
    • https://centrobrands.com/wp-content/plugins/super-forms/uploads/php/files/5d6d46f909213931f86029963ccbb506/dosadogexe.pdfIn PDF document text
    • https://btsis.com/upload/ckfinder/files/rodubiwaladi.pdfIn PDF document text
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/c6ptnkpem3nbb123tfpts85c4r/31411562446.pdfIn PDF document text
    • http://fc-junajted.com/upload/datoteke/4200157999.pdfIn PDF document text
    • https://www.lashharmony.co.uk/wp-content/plugins/super-forms/uploads/php/files/s0o865t66msu54hi2pgoljcut7/767506594.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b4f45c4ae2---50569790998.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a0d3304fa76---kepivosutojokafudete.pdfIn PDF document text
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cefe7cc2f9---8568329698.pdfIn PDF document text
    • https://regeneracion-capilar.com/wp-content/plugins/super-forms/uploads/php/files/3ea2c9b0813cdcb01374ea8a69aa1bde/90927353411.pdfIn PDF document text
    • http://crosswaysrecruitment.com/userfiles/file/pejapinuxoxozaxolejan.pdfIn PDF document text
    • https://satbietthu.com/luutru/files/woperap.pdfIn PDF document text
    • http://ecbpolska.pl/wp-content/plugins/super-forms/uploads/php/files/7f8a32115c68502bb0c685fe780511cb/66870662111.pdfIn PDF document text
    • https://apotekatia.ba/fajlovi/6463031401.pdfIn PDF document text
    • https://beaumont-residence.com/wp-content/plugins/super-forms/uploads/php/files/irojr497t5hlvb4tfcbjn43rpa/38591446942.pdfIn PDF document text
    • http://conelser.hu/fck_uploads/file/tejoloj.pdfIn PDF document text
    • http://herningbadintra.dk/app/webroot/upload/files/28495060789.pdfIn PDF document text
    • https://www.travelticket.com.au/wp-content/plugins/super-forms/uploads/php/files/5gqv8aeak1g9kka7tehci67aq6/75213132787.pdfIn PDF document text
    • https://taiwan-tiaya.com/upload/tiaya_official/files/ledegesoxininonuluf.pdfIn PDF document text
    • http://msamericapageant.com/clients/873634/File/vudarijixetatasutonataza.pdfIn PDF document text
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/160d8fdd0d0644---67792761948.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=self+confidence+tips+pdfPDF link annotation
    • http://lovewhereyoulv.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/0f847a0ddff60750e086f80adac2a62f/79453965844.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_off0000c47e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC47E 15000 bytes
SHA-256: 5b3885b3d77ffd7910663d94be47b5b4d159fdf6cb0d38161dd0be09db5445e4
font_01_sfnt_off0000e9f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9F6 10428 bytes
SHA-256: a88ce5718fbbf306e4c84f9f74f43287b64d96d510d0dd480179901e7831befa
font_02_sfnt_off000101aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101AA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1