Malicious PDF — malware analysis report

Static analysis result for SHA-256 65cd70f12ce06d87…

MALICIOUS

PDF

82.2 KB Created: 2021-09-11 02:06:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-22
MD5: 3d54889221113c7e84fa5512d957c317 SHA-1: e76647285333964b86e9ca77dce4e567b7e3994d SHA-256: 65cd70f12ce06d87c8bf23ea3dd7775196a88805f8469347c47e6d52ef8b2dcd
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://krisoc.ru/uplcv?utm_term=1+mod+apk PDF link annotation
    • http://cautrucpalang.vn/webroot/img/files/nuxotifuveluxoruzoposonan.pdfIn PDF document text
    • http://k9careclinic.in/ckeditor/ckfinder/userfiles/files/kexetefibukabogabatog.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/d98710d99de3b13de8c800f49deede53/guwipasavawakiv.pdfIn PDF document text
    • http://staceyasp.com/UserFiles/file/woritux.pdfIn PDF document text
    • http://woodwork.pl/ubezpiecz/obrazy/file/siluvaviluwifow.pdfIn PDF document text
    • http://architectureanddesign.it/userfiles/files/xivanoviketoj.pdfIn PDF document text
    • https://gloriamus.org/Uploads/userfiles/files/fuzajodenunisariwesug.pdfIn PDF document text
    • http://klaaswester.nl/img/file/wabeni.pdfIn PDF document text
    • http://moonlightmontessori.com/upload/files/7669381812.pdfIn PDF document text
    • https://prettygreekvillas.com/admin/fckeditor/editor/filemanager/connectofile/39648358786.pdfIn PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/4kigilemqd3om8f3utjqocv363/82551744918.pdfIn PDF document text
    • http://gruppocreta.com/userfiles/files/58793453229.pdfIn PDF document text
    • http://resheto.ru/users_images/fck/file/difolonajuj.pdfIn PDF document text
    • http://csim.jp/ckeditor/uploads/files/kilelorolu.pdfIn PDF document text
    • http://jnejendomsdrift.dk/userfiles/file/846254756.pdfIn PDF document text
    • http://apmnir.ro/fckfiles/file/suviwanejuxon.pdfIn PDF document text
    • http://worldsocialistpartyindia.org/ckfinder/userfiles/files/dotegoj.pdfIn PDF document text
    • http://tks-forever.com/upload/2021/09/05/file/gemapezosakimijazazex.pdfIn PDF document text
    • https://almuhja.com/ckfinder/userfiles/files/vevosorofonexewomasun.pdfIn PDF document text
    • http://landroverbh.com/ckfinder/userfiles/files/36735375740.pdfIn PDF document text
    • https://astefin.ro/ckfinder/userfiles/files/jukebasemunidolikinimob.pdfIn PDF document text
    • http://silver.jo/ckfinder/blanc/files/93784057846.pdfIn PDF document text
    • https://paperland.bg/uploads/file/zojozubokesobikosirow.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_off0000da49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA49 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f25b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF25B 19452 bytes
SHA-256: e98bb4bd54a76af959703a1408a037664944dfc45c71327b74114193c017d5b5
font_02_sfnt_off000125b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125B6 9860 bytes
SHA-256: 710932e859ace43df5cfe37d629c9d849e0c188ebc691f8419aace297f8bda45