Malicious PDF — malware analysis report

Static analysis result for SHA-256 83b4cc888ece7406…

MALICIOUS

PDF

76.4 KB Created: 2021-10-04 04:25:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: ad5d571da597c9a63d07395f02510707 SHA-1: 6bfcc0f0370ad2db07f22b6637055fa445db9769 SHA-256: 83b4cc888ece7406a3075360486da4603d430c3a9b45e3e9e1e0a694ad9b0f6f
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains a link farm with numerous URLs pointing to various domains, many of which are hosted on compromised CMS platforms or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document is designed to manipulate search engine results or direct users to potentially harmful content. The presence of multiple external URIs further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://drafthe.ru/uplcv?utm_term=indian+polity+by+laxmikant+5th+edition+pdf+download PDF link annotation
    • https://nvsrolko.org/ckfinder/userfiles/files/20217042574.pdfIn PDF document text
    • https://diamond-marketing.cz/soubory/vuzomibavixufawawu.pdfIn PDF document text
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/16138b8842a0cd---94972190085.pdfIn PDF document text
    • https://agrando.cz/files/file/26667057143.pdfIn PDF document text
    • http://niestachow.pl/data/aktualnosci_imgs/file/85875470800.pdfIn PDF document text
    • http://www.prunay-en-yvelines.fr/ckfinder/userfiles/files/39652860686.pdfIn PDF document text
    • http://slhospital.com/upload/fckeditor/file/92976314685.pdfIn PDF document text
    • http://elfobchod.cz/foto/Image/file/8900049395.pdfIn PDF document text
    • https://triyoga-tv.ru/userfiles/file/22623124604.pdfIn PDF document text
    • http://hotechike.com/files/files/92197336331.pdfIn PDF document text
    • http://geologocarmignani.com/userfiles/files/8218735736.pdfIn PDF document text
    • https://pioneerlift.com/upfiles/editor/files/vitozavadubaxogiviba.pdfIn PDF document text
    • http://auswallendorf.de/userfiles/file/xubokekogirefagutog.pdfIn PDF document text
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/2c0a16953cd00a90a947e82f279ed0f4/pavex.pdfIn PDF document text
    • http://kemenyseprosiklos.hu/upload/file/86700673842.pdfIn PDF document text
    • http://96rangjai.com/userfiles/file/jeluzukabususidapelojo.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/c714162521486bf2762f74e4bfc1abae/96349150616.pdfIn PDF document text
    • http://textingrights.com/userfiles/files/dirigadivejeru.pdfIn PDF document text
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/3cqnc97qrroq72j6kgu09ccmq4/92954729185.pdfIn PDF document text
    • http://sintellect.ru/Repository/file/zenafipatuvapujiloxapapaj.pdfIn PDF document text
    • https://basealimentare.it/webroot/files/fck_uploads/File/89255840745.pdfIn PDF document text
    • https://bititechnika.com/uploads/file/70130512338.pdfIn PDF document text
    • https://icrs-as.com/userfiles/file/robebipekexidininutigo.pdfIn PDF document text
    • http://piotrkowska77.pl/zdjeciafile/dulumiwiwegol.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_off0000baf7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBAF7 21240 bytes
SHA-256: 42e57f662ea16eb8097e02b887452a4d5542c62e98540f8d1ec87462dbc147d9
font_01_sfnt_off0000f21e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF21E 11112 bytes
SHA-256: 9421fb4cc8014e1f8e63a0b6cf7d948adeb5c71d3394e58d54a660701dee9dd9
font_02_sfnt_off00010bb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BB1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1