Malicious PDF — malware analysis report

Static analysis result for SHA-256 10d9853df5b011d3…

MALICIOUS

PDF

70.2 KB Created: 2021-09-25 06:31:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: aa809bb6b99127a8543cf1a9898d7302 SHA-1: e657f8b54ee84f9c6dd1317914f8f6b2b3f964b4 SHA-256: 10d9853df5b011d305412c14ac5df681b53eb6524ec74cf683668dedf66b2f16
166 Risk Score

Malware Insights

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

The PDF contains multiple heuristics indicating malicious intent, including random URL links and being part of a link farm on disposable hosting. The ML classifier and ClamAV detection strongly suggest this is a phishing or trojan delivery mechanism. The embedded URLs likely lead to the download of a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://laborke.ru/uplcv?utm_term=talking+tom+sky+run+download+apk PDF link annotation
    • http://chinhlytailieuluutru.com/media/ftp/file/pevuduzebukopeg.pdfIn PDF document text
    • https://catequesisnavarra.org/guiarte_userfiles/files/90744419086.pdfIn PDF document text
    • http://domadoma.cz/userfiles/file/kagokexaminatexudo.pdfIn PDF document text
    • https://thefencedocumentary.ca/adminfiles/file/89514825006.pdfIn PDF document text
    • http://dzstock.com/Upfiles/file/82024612049.pdfIn PDF document text
    • https://lecormier-menuiserie.com/www/upload/files/poxagos.pdfIn PDF document text
    • http://goldia.cz/data/file/miketa.pdfIn PDF document text
    • http://yurisolomko.com/userfiles/file/33028107548.pdfIn PDF document text
    • http://8njl.com/userfiles/files/diwidikuxopowudalotamexa.pdfIn PDF document text
    • https://padservhosting.com/userfiles/file/34447422152.pdfIn PDF document text
    • http://boek.se/bilder_umeny/File/jujuj.pdfIn PDF document text
    • http://kulturazebrak.cz/userfiles/xipalenamop.pdfIn PDF document text
    • http://dailyxedayhang.com/userfiles/files/sodivubodidutulu.pdfIn PDF document text
    • https://verticala.ro/images/userfiles/sitejubijikuduzol.pdfIn PDF document text
    • http://cocoon-source-harmonie.fr/public/file/kokijanomitotedo.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614e6520ac734---pavujabugudaj.pdfIn PDF document text
    • http://elma-itc.ru/!upload/files/vevopadapiromo.pdfIn PDF document text
    • http://ambulatorioveterinariosanfrancesco.com/userfiles/files/xifeme.pdfIn PDF document text
    • https://tradegateindia.com/userfiles/file/70181718437.pdfIn PDF document text
    • https://daaeportrett.no/upload/file/9019504440.pdfIn PDF document text
    • http://boston.pl/fck_pliki/file/namifosidetejenozakobatir.pdfIn PDF document text
    • http://ceresasrl.it/userfiles/files/99620742494.pdfIn PDF document text
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161304051a3bfc---2297550177.pdfIn PDF document text
    • http://goksirkrupskimlyn.pl/img/upload/files/99771228294.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_off0000b01d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB01D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c834.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC834 10956 bytes
SHA-256: 7fc5bc17d50cbfaecfff2d50939875a7756584ae533e43b5d6f4212544ce1664
font_02_sfnt_off0000e172.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE172 16400 bytes
SHA-256: bc3f9bccb89246cc4c1f7766b5f377dda43f6ffd867bad097443cd10a6c27c2b