Malicious PDF — malware analysis report

Static analysis result for SHA-256 0ebe3b0489688f99…

MALICIOUS

PDF

82.6 KB Created: 2021-09-18 07:56:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 5a48b3d52a5af15520b032eaaf7bffd5 SHA-1: 270948bed4abd451388f0bbba7b16106e20c863a SHA-256: 0ebe3b0489688f9994b3de46caec2bf47c576fed5b3b473cb79aac690365225b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to multiple external URLs, including suspicious domains like 'coretry.ru' and 'avtokit116.ru'. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports the conclusion that this PDF is designed to host and distribute malicious links, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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=twelve+sky+mobile+apk PDF link annotation
    • http://avtokit116.ru/!upload/files/xalosivokusakefovuze.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1613c84f7c03f9---23680037406.pdfIn PDF document text
    • https://pulsekb.ru/admin/ckfinder/userfiles/files/70677461647.pdfIn PDF document text
    • http://3wsystems.com/shipinc/userfiles/files/57962617500.pdfIn PDF document text
    • http://systempro.kr/userData/board/file/nepizipamozetesa.pdfIn PDF document text
    • http://woodlander.sk/grafika/file/62554181220.pdfIn PDF document text
    • http://www.bluewhaleline.com/image/upload/File/kanutirixakunedolob.pdfIn PDF document text
    • http://krainaogrodow.eu/zdjecia/fck/file/15770147972.pdfIn PDF document text
    • http://laarakkers.com/ckfinder/userfiles/files/wejijetedenat.pdfIn PDF document text
    • http://harekatmemuru.com/images/Media/files/72081431641.pdfIn PDF document text
    • https://netcsemege.hu/ckfinder/userfiles/files/pemurunej.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/161403b1762b96---21678546934.pdfIn PDF document text
    • http://malir-naterac.info/UserFiles/File/ditapagenuketaxuzog.pdfIn PDF document text
    • http://zovsh.com/Uploadfiles/files/sumutevugek.pdfIn PDF document text
    • http://wdnederland.nl/file/62404395447.pdfIn PDF document text
    • http://wpscrm.in/uploaded_files/userfiles/files/49903036438.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1613dce74bf022---73542911897.pdfIn PDF document text
    • http://quincy.pl/ckfinder/userfiles/files/91428014782.pdfIn PDF document text
    • http://ebus.cn/up_file/file/zoril.pdfIn PDF document text
    • https://artesapanaderia.xyz/aym_image/files/85704650841.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613509c517c6b---92031442070.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_off0000db8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB8F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f3a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3A6 10572 bytes
SHA-256: 53525aa2ce846fad3c6cccf8173369554203c537951ebc016af9d2e3c0285497
font_02_sfnt_off00010ba8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BA8 18864 bytes
SHA-256: 46b65564bd04c2f595ec3d022bdf3b7c272e7aee024d44504e53ee3d556cca82