Malicious PDF — malware analysis report

Static analysis result for SHA-256 51fcb51616d42a2a…

MALICIOUS

PDF

83.5 KB Created: 2021-09-17 14:23:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 0af6c8cb52b7b57d4b7a0260871b9195 SHA-1: e23d8eb1418dc3a971147488e1917671a754b5ae SHA-256: 51fcb51616d42a2a80382717cc084284340e780d540b8a94d935c3e6ce873181
156 Risk Score

Malware Insights

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

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It functions as a link farm, with numerous URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious content. The PDF structure and embedded links are consistent with phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • 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.
  • 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://philabc.ru/uplcv?utm_term=fifa+14+mobile+play+store PDF link annotation
    • http://youzedu.com/ckimages/files/20210912103323531130.pdfIn PDF document text
    • https://drjou-vc.com/upload/files/83441597454.pdfIn PDF document text
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140711329a52---munewezinadinibopale.pdfIn PDF document text
    • https://yifff.se/userfiles/file/bojawulafabezufemojigak.pdfIn PDF document text
    • http://seghers.kr/data/editor/file/5823085546141fbc8a0561.pdfIn PDF document text
    • https://nazragame.com/calisma2/files/uploads/lejilofawofuwonomaje.pdfIn PDF document text
    • http://beiks.info/public/file/kuteninivevud.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613f0f9dd26f5---rewedexoremosok.pdfIn PDF document text
    • https://iwanbim.iwan.co/userfiles/files/vutopojagopoxa.pdfIn PDF document text
    • https://cicimanis.com/contents/files/71211063906.pdfIn PDF document text
    • http://vanguardhungary.hu/userfiles/file/10531010739.pdfIn PDF document text
    • https://opsclown.it/ckfinder/userfiles/files/lomax.pdfIn PDF document text
    • http://fbrasil.com/userfiles/file///nemalelezor.pdfIn PDF document text
    • https://rumusjitu.com/contents/files/76543143561.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/161384a8611c41---95180762168.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1613fd62f3c178---kovidululusawop.pdfIn PDF document text
    • http://lngpetro.com/userfiles/file/zadipebi.pdfIn PDF document text
    • http://bisenzia.it/userfiles/files/5527206082.pdfIn PDF document text
    • http://yavuzselimvakfi.org/resimler/site/files/rudafifubojamumunogaz.pdfIn PDF document text
    • http://khonggianmang.com/upload/files/kejukiruduxirebinebabefiw.pdfIn PDF document text
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/4jv4cahvmldgqqvk8clg6762aq/46755408240.pdfIn PDF document text
    • http://seoulmenu.com/uploads/files/45254016014.pdfIn PDF document text
    • http://progetec.org/userfiles/files/zumixatelewijivemitimufag.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_off0000dfef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFEF 18236 bytes
SHA-256: 0968236d304635ef6e5959345ecd0cc31c0d29d031fcc78b56977c11c83a1253
font_01_sfnt_off00010f71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F71 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012788.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12788 10776 bytes
SHA-256: fa23a89037698393c514038fdb62170169b486ffd6d1b51dc27b2d2b384f15a5