Malicious PDF — malware analysis report

Static analysis result for SHA-256 86841ff214979e93…

MALICIOUS

PDF

75.5 KB Created: 2021-09-12 18:45:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 94afcfa1f43fa148a4c8daf951566776 SHA-1: 66ccbe3cdb3787ae50c22a8d49c74cfb50d07ee9 SHA-256: 86841ff214979e933e64e26a789733d89389a6cd4f6b9831620f172b3e9af361
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm on disposable hosting, with multiple URLs pointing to compromised CMS upload directories. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the presence of numerous external links strongly suggests an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://zabradli-znerezu.cz/userfiles/file/mixugar.pdf In PDF document text
    • http://gesht.ru/admin/ckfinder/userfiles/files/84926297066.pdfIn PDF document text
    • http://retco.ge/ckfinder/userfiles/files/fadifak.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/44247aeb21ba919a26f6814f1180fd92/wiwewejanel.pdfIn PDF document text
    • http://tjsyjdq.com/v15/Upload/file/20219111853208629.pdfIn PDF document text
    • http://konditsionery-zheleznodorozhnyi.ru/upload_picture/file/33841174983.pdfIn PDF document text
    • https://vitanov.rs/files/6076943071.pdfIn PDF document text
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/ba729a66d6e098403968513237a05f71/77024506809.pdfIn PDF document text
    • https://bahceneryaman.net/public/content-images/files/49262995600.pdfIn PDF document text
    • http://z-sinpro.com/upload/files/resaxidofuzapez.pdfIn PDF document text
    • http://klubalfa.org/img/userfiles/file/25978545634.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16133d5b52b37b---vusaxajidutufeva.pdfIn PDF document text
    • http://rilta.net/userfiles/files/vutinafarepifipivimatu.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613de6c26ca89---guzebitibag.pdfIn PDF document text
    • https://centaur.vri.cz/docs/files/78998485852.pdfIn PDF document text
    • http://noithatphathuy.com/Images_upload/files/bavaze.pdfIn PDF document text
    • https://aynadakikemalizm.com/resimler/files/6497650446.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134177a982ee---batupozawel.pdfIn PDF document text
    • http://yonseri.org/userfiles/files/sozutisaxugizutuve.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131d4b8d9f62---ligizet.pdfIn PDF document text
    • http://ilksolar.com/Images/Media/files/judosedexi.pdfIn PDF document text
    • http://www.onlinenieuwsbriefversturen.nl/gebruikers/afbeeldingen/85439253433.pdfIn PDF document text
    • http://myphamasia.net/upload/files/pilumevotixisozulinupido.pdfIn PDF document text
    • http://bedrucken24.de/userfiles/file/26823597347.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=tom+hero+dash+apkPDF link annotation
    • 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_off0000bdd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDD9 10372 bytes
SHA-256: 4910534d7d1dd01dfe2bc9bb695e592f54cd59997ec8509a9a79e7df7acd8d43
font_01_sfnt_off0000d548.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD548 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ed5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED5A 19784 bytes
SHA-256: df15eb4554c09f10abc49b37ec9330484a458c66cb5c579f24579263d833185d