Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc86e3994238d7fb…

MALICIOUS

PDF

73.6 KB Created: 2021-10-08 00:04:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: c03a2590bfa940170fe644101e6a489c SHA-1: 0e50ab3f3075edd9c041397ae7675fe1288a1545 SHA-256: bc86e3994238d7fbcbef9072b795fb4b6acc113f4800e836d21ec2d2482920c6
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious intent. The PDF contains numerous external URIs and is described as a link farm hosted on disposable domains, suggesting a phishing or malware distribution scheme. Although no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics point towards the document's primary function being to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9909

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://queure.ru/uplcv?utm_term=arbitrary+constant+of+differential+equation PDF link annotation
    • https://brs.jo/userfiles/files/77085618228.pdfIn PDF document text
    • https://coebmsf.com/userfiles/file/91724771809.pdfIn PDF document text
    • http://tbeaindia.com/userfiles/file/xetilazimo.pdfIn PDF document text
    • http://digifast.cz/userfiles/namovukivetatobunol.pdfIn PDF document text
    • https://univerosg.com/ckfinder/userfiles/files/wenetegukinimogeni.pdfIn PDF document text
    • http://dlabiura.kbo.pl/ckfinder/userfiles/files/20548408507.pdfIn PDF document text
    • http://www.vegagastro.pl/upload/file/bexitoga.pdfIn PDF document text
    • http://ambulatorioveterinarioilprato.eu/userfiles/files/xenibefemugotofikefugese.pdfIn PDF document text
    • http://kramnyca.info/img/upload/editor/file/zulis.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/16148a62c2fa22---18237822895.pdfIn PDF document text
    • http://citranco.com/users/files/69582860641.pdfIn PDF document text
    • http://abcbyspu.com/ckfinder/images_store/files/musanupenezazoterule.pdfIn PDF document text
    • https://www.wemservice.com/ckfinder/userfiles/files/xatipefagukonenopube.pdfIn PDF document text
    • http://jkbprivateiti.com/userfiles/file/gewulituselinagut.pdfIn PDF document text
    • https://pokereshop.cz/data/file/23900552666.pdfIn PDF document text
    • https://bhopalliteraturefestival.com/mpsdp/uploads/files/20929978712.pdfIn PDF document text
    • http://etalentlink.com/uploadfile/file///2021091717144154.pdfIn PDF document text
    • http://sherwoodonionfestival.com/ckfinder/userfiles/files/fipazekajonosurifijizu.pdfIn PDF document text
    • http://yotlist.com/uniformkontakt/userfiles/image/files/valokakoxorel.pdfIn PDF document text
    • http://uforoi.com/app/webroot/uploads/files/wemok.pdfIn PDF document text
    • http://ahzgbh.news-read.com/upload/files/nodetuzufofibo.pdfIn PDF document text
    • https://nikunjfoundation.org/ckfinder/userfiles/files/vorimimobakepixerevewukag.pdfIn PDF document text
    • https://haciendaloscipreses.cl/upload/file/sejemixorizigu.pdfIn PDF document text
    • https://botroul.be/uploads/dasolufodu.pdfIn PDF document text
    • https://italvaping.com/file/pelesosoriwapezow.pdfIn PDF document text
    • https://maurinet.com/userfiles/file/19901209391.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_off0000babe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBABE 16960 bytes
SHA-256: 1417b502ee2165464242cdb0ce3ee276252f949bb39019425f76341050b2e6a8
font_01_sfnt_off0000e68b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE68B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fea2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEA2 10948 bytes
SHA-256: eb58410edb1991e568c548ad714b6871b402cf2b9e01e982826532b01d405bd8