Malicious PDF — malware analysis report

Static analysis result for SHA-256 636f33df93a6b2f0…

MALICIOUS

PDF

73.4 KB Created: 2021-09-18 03:25:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7a78c104dff0613ee1d7963454c49d42 SHA-1: 6f3dcaae8fe484bb9ef37558a7daf8037c2f242c SHA-256: 636f33df93a6b2f01782c4c9e902d643b9157407d64fca682e0254c90ffdedd2
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which are hosted on disposable domains and appear to be part of a link farm, suggesting a phishing or scam campaign. The presence of external URIs and the overall structure point towards an attempt to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://medvor.ru/uplcv?utm_term=get+rid+of+subtitles+on+firestick
    • http://terezszilvia.com/images/uploaded/file/63826973326.pdf
    • http://askaudit.ru/price/sadivifa.pdf
    • http://dh-life.com/ckfinder/userfiles/files/kuranume.pdf
    • http://dansensvenner.dk/imagesfile///koxuzafufufolet.pdf
    • https://honghow.com/ckfinder/userfiles/files/karogojitodif.pdf
    • https://hamasataccessories.com/userfiles/files/tuvudavegosamizamaguluvox.pdf
    • http://imhyuk.com/imhyukeditor/userfile/file/musaronixoj.pdf
    • https://cristalparkhotel.com.ve/ckfinder/userfiles/files/39292169812.pdf
    • https://digireg.ru/upload/27514109684.pdf
    • http://onroerendgoedindex.nl/images/uploads/92113615418.pdf
    • http://hooleihomes.com/cms_images/file/65614174821.pdf
    • http://trubaopt.ru/content/file/45594579423.pdf
    • http://ettermanenterprises.com/ckfinder/userfiles/files/jitige.pdf
    • https://dienmayminhchau.vn/uploads/news_file/42591803960.pdf
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/relumuka.pdf
    • https://willes-gb.com/uploads/files/202109012220103840.pdf
    • http://www.peritaonline.es/ckfinder/userfiles/files/37193437299.pdf
    • https://foundationkuzmanov.com/files/segomobupaxa.pdf
    • https://igruppe.no/ckfinder/userfiles/files/jokivuvexamuz.pdf
    • https://www.savininkai.lt/ckfinder/userfiles/files/64191681821.pdf
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/eca816c8cc307762871326b932cfb75b/mufiv.pdf
    • https://selispin.com/calisma2/files/uploads/34118203840.pdf
    • https://www.ruchya.com.tw/upload/files/66236612189.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bad5.bin
03384ec7983cd2c1a65c0512a245d67cac993b8f2c9ddf3ecf378491ef759b28
pdf-font-stream PDF embedded font (sfnt) at offset 0xBAD5 10676 bytes
font_01_sfnt_off0000d372.bin
9d7391e2ed6e90f8ebb65f81f62879b3b24aabf9b506cc30ee3b97f5145cf0c7
pdf-font-stream PDF embedded font (sfnt) at offset 0xD372 17324 bytes
font_02_sfnt_off0000fffd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFFD 16792 bytes