Malicious PDF — malware analysis report

Static analysis result for SHA-256 81ff2a20f10d2fe1…

MALICIOUS

PDF

75.7 KB Created: 2021-09-21 16:08:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: f7e32d063630ba486b3e50d81a898322 SHA-1: b782cb52aee62d4f074172f1f8da975c2ddc15b4 SHA-256: 81ff2a20f10d2fe1373a1b672d62fe8a72aec73b6d1662832109ca1187139a6b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to compromised websites or disposable hosting, characteristic of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or SEO spam. No scripts were extracted, but the PDF structure itself facilitates redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://coretry.ru/uplcv?utm_term=how+to+restore+deleted+camera+pictures+on+android PDF link annotation
    • http://ciaomamma.hu/editor_up/kuzoxuzozefi.pdfIn PDF document text
    • https://padservhosting.com/userfiles/file/36630070006.pdfIn PDF document text
    • http://tasarimak.com/ckfinder/userfiles/files/kufidulam.pdfIn PDF document text
    • https://digiconelectronics.com/media/jirawobum.pdfIn PDF document text
    • https://jamisonfurnace.ca/userfiles/files/68811857255.pdfIn PDF document text
    • http://ptk-tent.ru/userfiles/file/ludifa.pdfIn PDF document text
    • http://naasschoolofmotoring.com/fckeditor/userfiles/file/jezitisutevezipofip.pdfIn PDF document text
    • http://vangphutai.com/images/uploads/files/mokeposagesexepunuro.pdfIn PDF document text
    • http://bogaarchitetti.it/userfiles/files/75900633868.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/l4ifupb3e43puo5j4e07ucd1hv/pujabawoxurivibubivo.pdfIn PDF document text
    • http://manu-transport.com/documents/file/repuvafarariwivozatil.pdfIn PDF document text
    • https://aarhuskortet.dk/images/file/lavuroxuti.pdfIn PDF document text
    • http://dancephoto.ru/userfiles/files/tabasoxuvarunosejokefuzek.pdfIn PDF document text
    • http://bratislava.topenglish.sk/app/webroot/gallery/files/19232467422.pdfIn PDF document text
    • https://chongtham68.com/app/webroot/uploads/files/64945445145.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131b8b312ed6---15373334537.pdfIn PDF document text
    • http://2222.netsociality.com/upload/files/fatat.pdfIn PDF document text
    • http://namngonviet.com/user-/files/60643678712.pdfIn PDF document text
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16140c353a8d97---32599977280.pdfIn PDF document text
    • http://boekenwinkelindex.nl/images/uploads/71618488567.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/ffqrqudt9dglf33pl63dh4ia03/mizedowar.pdfIn PDF document text
    • http://skipjackpoke.com/ckfinder/userfiles/files/26484595837.pdfIn PDF document text
    • https://thieumaunao.vn/workspace/develop/uploads/ck_upload/files/88515725055.pdfIn PDF document text
    • http://goldenbaycruisesagent.com/userfiles/file/99547237799.pdfIn PDF document text
    • http://gurgaontaxi.com/pa/trainstation/uploads/image/file/ritakobiwuvojepif.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_off0000c575.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC575 16296 bytes
SHA-256: ba24e3c944c79c568069440613716de96f9fbcdf2759fb09b27c5bbb4e8aec7c
font_01_sfnt_off0000efa4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFA4 10852 bytes
SHA-256: 697b528f1fd5f00f608874a430213cbb5c8d3b8863264b9dc5618969294565b4
font_02_sfnt_off000108b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108B5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1