Malicious PDF — malware analysis report

Static analysis result for SHA-256 d53e3e072f494b54…

MALICIOUS

PDF

82.1 KB Created: 2021-10-12 18:46:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 0b07893829c323e543d78406459b9554 SHA-1: e6e58f9e053d0c97edeb66b345f7836f176a4bee SHA-256: d53e3e072f494b54bc7e586a82d47a24ec812ed4a640f5dde954e0fe90dd8304
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, with heuristics indicating it functions as a link farm pointing to numerous external PDF files. The presence of multiple unknown URLs suggests an attempt to distribute further malicious content or conduct phishing. No scripts were extracted, but the overall structure and heuristic firings strongly indicate a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://enjoy.sk/editor_uploads/system/files/46155536212.pdf In PDF document text
    • http://topbondtape.com/uploadss/file/wevav.pdfIn PDF document text
    • https://cpsguffanti.it/uploads/file/79589708744.pdfIn PDF document text
    • http://chickendaylacrescenta.com/uploads/files/wisuxamavekatevofowufela.pdfIn PDF document text
    • https://morethancars.eu/uploads/edytor/file/livinarodovunuseposonovem.pdfIn PDF document text
    • http://matrixpaint.com/ckfinder/userfiles/files/jubepatu.pdfIn PDF document text
    • http://yuhao-tech.com/userfiles/file/88384085801.pdfIn PDF document text
    • http://ajk-opakowania.eu/upload/fck/file/zaxomizezeteredisopakogi.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/161542b9a98155---jutuviwosij.pdfIn PDF document text
    • http://almawred-sy.com/files/adminfiles/files/wijoja.pdfIn PDF document text
    • http://northcity.rs/slike/files/rebesu.pdfIn PDF document text
    • http://ip-golubev.ru/ckfinder/userfiles/files/2284169405.pdfIn PDF document text
    • http://balalajka.nu/media/77401372789.pdfIn PDF document text
    • https://gifarlcm.com/upfiles/editor/files/bitufudipanurepesula.pdfIn PDF document text
    • https://cylinder96.ru/admin/ckfinder/userfiles/files/97169867546.pdfIn PDF document text
    • http://pcccphucvinh.com/upload/files/pokezo.pdfIn PDF document text
    • http://siddharpeedam.org/userfiles/file/In PDF document text
    • http://npas.ru/pic/file/62366778442.pdfIn PDF document text
    • https://namhunglogistic.vn/site/files/75700717209.pdfIn PDF document text
    • https://nepaltrekkinginhimalaya.com/assets/userfiles/files/99666358150.pdfIn PDF document text
    • https://ikansambel.com/contents/files/xijilodubojago.pdfIn PDF document text
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/947bd1ed36c4734541f02deb0ce3b90f/legudeloviratixadisilix.pdfIn PDF document text
    • http://allergyc.news-read.com/upload/files/81958857240.pdfIn PDF document text
    • https://www.jakketoes.be/ckfinder/userfiles/files/43032080395.pdfIn PDF document text
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/66006653191.pdfIn PDF document text
    • http://feedproxy.google.com/~r/MbOu/~3/cmwvf4RlXg4/uplcv?utm_term=unit+14+reading+guide+social+psychologyPDF 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_off0000db60.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB60 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f377.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF377 11144 bytes
SHA-256: 619c39e02054eb27328b9e61a0cec9777cd402314cf0c9bee75ff0bfddaafee8
font_02_sfnt_off00010d55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D55 17660 bytes
SHA-256: 685300c15be7f74963010d61ed529d21d2ad63e472bd02fe87b03fdbed05cad4