Malicious PDF — malware analysis report

Static analysis result for SHA-256 25c0d42219c388f2…

MALICIOUS

PDF

73.1 KB Created: 2021-10-01 03:47:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 64bdf239099903589b7975c2920bb20f SHA-1: a1ca9383e73016784e50e66d427547ed3a8bc926 SHA-256: 25c0d42219c388f24c76978d22c2e4373631ebf6501344ab7e658f40b39dd513
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to disposable domains, indicating a link farm designed to redirect users. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' confirms this behavior, suggesting the document's primary purpose is to host these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9827

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 https://smidgel.ru/uplcv?utm_term=gangstar+5+hack PDF link annotation
    • https://ego-sofa.tw/uploads/files/202109090534225062.pdfIn PDF document text
    • https://bokaichenyu.com/upload/files/19491073621.pdfIn PDF document text
    • http://aivieksteslaivas.lv/userfiles/file/82311423524.pdfIn PDF document text
    • https://goodluckfishing.com/ckfinder/userfiles/files/zefijorase.pdfIn PDF document text
    • http://zaun-produzent.de/userfiles/file/80180459494.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16152b05b5495b---befiva.pdfIn PDF document text
    • http://pinzimoniofiumicino.eu/userfiles/files/fuselimez.pdfIn PDF document text
    • https://dodatkireklamowe.pl/web/uploads/files/85572874360.pdfIn PDF document text
    • https://cailux.lu/userfiles/files/wosubapasixej.pdfIn PDF document text
    • http://3q1p.com/upload/file/210924024940136915ii1991j674uj.pdfIn PDF document text
    • http://caigeshi.com/uploadfile/file/2021090912445573499.pdfIn PDF document text
    • https://everestart.com/images/stories/file/49413080371.pdfIn PDF document text
    • https://ce-mi.pl/uploads/userfiles/files/makobinalodavejivefurim.pdfIn PDF document text
    • http://travelsi.ru/ckfinder/userfiles/files/66219298505.pdfIn PDF document text
    • https://asiantms.com/ckfinder/userfiles/files/wopij.pdfIn PDF document text
    • https://hyosung-gulf.com/uploads/file/towaderiti.pdfIn PDF document text
    • http://chatyzvule.cz/uploads/19916144355.pdfIn PDF document text
    • http://bollnas.boj.se/uploads/userfiles/files/35649594514.pdfIn PDF document text
    • http://firegallery.ru/img/upload/majamujusod.pdfIn PDF document text
    • http://limuzine.md/userfiles/file/mosenino.pdfIn PDF document text
    • http://france-ex.com/images/blog/file/porizijibelefigur.pdfIn PDF document text
    • https://10kshot.com/customerinterview/ckfinder/userfiles/files/vigadipefekomakinexiteb.pdfIn PDF document text
    • http://dobre-jaja.com/Upload/file/80669226256.pdfIn PDF document text
    • http://allier.proximeo.com/ckfinder/userfiles/files/83379061675.pdfIn PDF document text
    • http://bloodfaces.de/attachment/file/forazudosivajunopanufibe.pdfIn PDF document text
    • http://apnm.indexint.net/ckfinder/userfiles/files/juzigep.pdfIn PDF document text
    • https://www.thc.gda.pl/ckfinder/userfiles/files/42092487210.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_off0000b627.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB627 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ce39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE39 19668 bytes
SHA-256: e5bcd8d61d52138cdb98ef422f42c3b740c6dee17da742596dcb959041920b66
font_02_sfnt_off0000ffb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFB3 10384 bytes
SHA-256: dc4542e1dc3007dd6aca64850e55c591c43834afd8586d438ee0705344824b25