Malicious PDF — malware analysis report

Static analysis result for SHA-256 cffce791e748ba9a…

MALICIOUS

PDF

69.7 KB Created: 2021-09-23 02:30:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 58baac3b8500e5134c12cbcaf41b9875 SHA-1: bec92cdba4624f40b40e2b79eb7bbb5fa7073188 SHA-256: cffce791e748ba9a9eaff2aeb7d252e8ca7b000efe8f3f49f354eba865589d0a
126 Risk Score

Malware Insights

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

The PDF sample was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple disposable domains. While no scripts were explicitly extracted, the PDF structure and its association with link farms suggest it's designed to redirect users to malicious sites, potentially for phishing or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 http://wksx.top/images/userfiles/file/54307516608.pdf In PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/7baed9caf0bca6d9494cfd188b4e24ba/joxixifivulowopetavizi.pdfIn PDF document text
    • http://fedime.org/imagenes/84782920625.pdfIn PDF document text
    • https://zooiguana.pl/app/webroot/media/files/19747195214.pdfIn PDF document text
    • http://hoaisonland.vn/upload/files/6020918831.pdfIn PDF document text
    • http://spodne-pradlo-2bpoint.sk/UserFiles/File/30856710758.pdfIn PDF document text
    • http://kemnhapkhau.com/upload/files/tirosotowi.pdfIn PDF document text
    • http://hytechplus.com/userfiles/file/kogavubivuniwipubuwaxop.pdfIn PDF document text
    • http://objets.immoweiss.lu/userfiles/files/gulopixokisalirusinusodap.pdfIn PDF document text
    • http://kuwaited.com/cote_dor_import/admin/ckfinder/userfiles/files/65443767915.pdfIn PDF document text
    • http://goang-hann.com/uploads/files/202109090129322055.pdfIn PDF document text
    • http://xn--3e0b556bhrbowi6undva.com/ckupload/files/kuboduxobowonusaru.pdfIn PDF document text
    • http://aygroupmuh.com/image/files/65146539500.pdfIn PDF document text
    • http://abovomedia.hu/_user/file/povumafabudid.pdfIn PDF document text
    • http://hdurmuslar.com/images_upload/files/9573419886.pdfIn PDF document text
    • http://tiendanatacion.com/noticias/files/12022983047.pdfIn PDF document text
    • https://smilaxlabs.com/userfiles/files/60183674572.pdfIn PDF document text
    • https://mangallagn.com/images/file/42210940918.pdfIn PDF document text
    • https://hunglivet.com/uploads/files/202109010120209338.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/161394fe55b9ff---89731624772.pdfIn PDF document text
    • https://kungfuclasshongkong.com/louis/taichi/ckfinder/userfiles/files/dumagori.pdfIn PDF document text
    • https://rcvizovice.cz/ckfinder/userfiles/files/63054951942.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=boost+net+speed+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_off0000b44a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB44A 10392 bytes
SHA-256: f86dd0c5e212ffe0544e7a83a51556c8773bfda309d5dc98180fdb3f8278e7a6
font_01_sfnt_off0000cbf0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBF0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e402.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE402 14928 bytes
SHA-256: bcfb1a9a0ff6aa4aff2762df0ac8997a305150c6a6ce126bed93b5fdfe197c31