Malicious PDF — malware analysis report

Static analysis result for SHA-256 85c7633be744c6db…

MALICIOUS

PDF

71.2 KB Created: 2021-09-10 11:28:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 507afe1660c0ae26aaf468867f701717 SHA-1: a4c19a40e2ac96190755232a4263d7c996e43916 SHA-256: 85c7633be744c6db8375e332da195464b5ada8521fe882b6f2d7bb4e9e773b4c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The PDF contains numerous embedded URLs, many of which point to potentially malicious domains or are part of a link farm. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest an attempt to lure users to external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nikosdimos.gr/userfiles/file/jopetotamob.pdf In PDF document text
    • https://psfund.org/public/uploads/files/cms_files/rovitolejosulujoraxanomo.pdfIn PDF document text
    • http://xn--oy2b19v1mb1yi.com/userfiles/file/gorejoputabiwuneziwu.pdfIn PDF document text
    • http://www.kotolantopeni.cz/files/22861175986.pdfIn PDF document text
    • http://fitnessklub-impuls.pl/uploads/assets/file/tamejuti.pdfIn PDF document text
    • http://myucmas.com/userfiles/file/suwapelimotapalumizuw.pdfIn PDF document text
    • http://tries.cz/media/images/upload/file/55743359686.pdfIn PDF document text
    • http://tko.wavedev.net/img/files/files/reliwubi.pdfIn PDF document text
    • http://hangquangauto.com/files/39582864640.pdfIn PDF document text
    • https://ildiko-szepsegszalon.hu/userfiles/file/30902267488.pdfIn PDF document text
    • http://lauraestetica.com/userfiles/files/rudolivuxerenemozubi.pdfIn PDF document text
    • https://keralatemples.info/ckfinder/userfiles/files/fubinebesadukivudoga.pdfIn PDF document text
    • http://slstudio.it/userfiles/files/54140249638.pdfIn PDF document text
    • https://batikatravels.com/userfiles/file/bowiwururixatal.pdfIn PDF document text
    • http://i-akparat.kz/ckfinder/userfiles/files/naranivuwatoveku.pdfIn PDF document text
    • https://www.domaine-de-la-ferme.fr/ckfinder/userfiles/files/digip.pdfIn PDF document text
    • https://sskundal.com/userfiles/file/zajisutibakamupuj.pdfIn PDF document text
    • http://eyela.kr/uploadfile/fckeditor/file/39971660971.pdfIn PDF document text
    • https://hatinhjobs.com/upload/files/98688364988.pdfIn PDF document text
    • https://susta.vn/userfiles/file/59523805780.pdfIn PDF document text
    • http://brandiassociati.it/userfiles/file/tikufikimabivanirob.pdfIn PDF document text
    • http://gld-lining.com/user_img/files/sixixezisosiraw.pdfIn PDF document text
    • http://omni-links-europe.com/images/blog/file/13577238130.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/ja8v6p82h85udq0iat1c9srmf1/40752242104.pdfIn PDF document text
    • http://smelawservice.com/file_media/file_image/file/7444992067.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=esconder+iconos+en+androidPDF 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_off0000b8ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8CA 15904 bytes
SHA-256: 00f832175b9ff1eba3243ebd2efa686b95af0dd3d13bc16c6cd03f78d3593586
font_01_sfnt_off0000e002.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE002 10204 bytes
SHA-256: 5e39a99d5d98b5b46d71a7d747e3fd76209f0d9bd76e4ca85e1f032af0981d30
font_02_sfnt_off0000f6f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1