Malicious PDF — malware analysis report

Static analysis result for SHA-256 c871efa95b929b35…

MALICIOUS

PDF

78.0 KB Created: 2021-09-23 09:19:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 4cd833bebe2f8227f25eb786f913f025 SHA-1: 7e5dee5edae6eb7a9b2b722de81966681aedea01 SHA-256: c871efa95b929b355fa96a7f65cf8d98c5b83c3c2b9aa960b24c83512eafc3bd
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. The PDF contains numerous embedded URLs, many of which point to disposable domains and are structured as a link farm, a common tactic for distributing malicious content or phishing pages. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly indicates this malicious intent. While no scripts were extracted, the PDF structure and numerous external links suggest it is designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://allytemp.ru/uplcv?utm_term=bigwinner+apk+download PDF link annotation
    • http://j-line.ca/fck_upload/file/54207417948.pdfIn PDF document text
    • http://chhattisgarhsanskritboard.in/sharpinstitute/images/files/vunetejenepuxixesen.pdfIn PDF document text
    • https://dintek.eu/uploads/file/zupokumalutedekijowutev.pdfIn PDF document text
    • http://www.cddfct.com/up_files/file/gisuzofevogok.pdfIn PDF document text
    • http://americasbestmanassas.com/uploads/files/jatosajenisezora.pdfIn PDF document text
    • https://podimercrm.com/img/files/kitunexidavifisolozuxareg.pdfIn PDF document text
    • http://veterky.ru/ckfinder/userfiles/files/gupekasami.pdfIn PDF document text
    • http://bc-arman.kz/ckfinder/userfiles/files/87425411350.pdfIn PDF document text
    • http://pulsarvn.com/media/ftp/file/lejafovibetababezez.pdfIn PDF document text
    • https://seikai.jp/free_images/files/lusefalizazafevof.pdfIn PDF document text
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/eff9e66d12a35acac5606dc180bae334/22088408777.pdfIn PDF document text
    • http://vitalenzyme.com/uploads/fckupload/file/42461619110.pdfIn PDF document text
    • https://olterus.org/contents/files/59983646863.pdfIn PDF document text
    • https://benmoonpharma.com/userfiles/file/46945916727.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/1613027d7c3736---pemifewokorurajerex.pdfIn PDF document text
    • http://antracit.topmebli.com/content/xuploadimages/file/napafexigoguvimajepi.pdfIn PDF document text
    • http://optykglowacki.pl/obrazki/files/88328053397.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613516012d841---85921876122.pdfIn PDF document text
    • http://anabakorea.jp/userfiles/file/lokafotuduke.pdfIn PDF document text
    • https://taiwan-tiaya.com/upload/tiaya_official/files/fugas.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_off0000ccdf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCDF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e4f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4F6 10532 bytes
SHA-256: a2589365dc3a7cc97e91ff5366f206fbe5c39c01ef414953f4760bd2c6bbeeb5
font_02_sfnt_off0000fcd8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCD8 18076 bytes
SHA-256: 2d36eb6ee2822830b59da3ccf116128b331fe3735ea11ad8a8f3a13a20594175

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