Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b55967c56bf97b5…

MALICIOUS

PDF

79.1 KB Created: 2021-09-15 16:51:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 31dccc1942dbde355502ba9fd80db2bb SHA-1: 6a431b07bf4d70f3fd377f81a1c82b0ffe58d0c4 SHA-256: 9b55967c56bf97b512c08f01e59af6c6ac0d8dff4bc21aaf4662b98f4154d38c
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, with a critical heuristic indicating it's a phishing trojan. It contains embedded JavaScript and numerous external URIs, suggesting it's designed to redirect users to potentially malicious sites. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further indicates a link farm structure, commonly used for phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://fond.ru/userfiles/file/kenadodogarikodusuxaje.pdf In PDF document text
    • http://delfosventures.eu/userfiles/files/sibexizawob.pdfIn PDF document text
    • http://www.sana-anong.com/ckeditor/ckfinder/userfiles2/files/2679674781.pdfIn PDF document text
    • http://gamaxmotor.cz/data/dokumenty/30240554084.pdfIn PDF document text
    • http://dxline.eu/userfiles/file/jiledoromami.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/161390850b3a17---76574910076.pdfIn PDF document text
    • http://tandartsindex.nl/images/uploads/74942524344.pdfIn PDF document text
    • http://rulife.ru/ckfinder/userfiles/files/24868842354.pdfIn PDF document text
    • http://kcpsystem.com/userData/board/file/42992146521.pdfIn PDF document text
    • http://ecoevopublisher.com/files/upfiles/file/tumepunaxazekirarimajusiw.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613abca2270cf---23404807778.pdfIn PDF document text
    • https://asharfilalkulfi.com/ckfinder/userfiles/files/tozakaxalarafifi.pdfIn PDF document text
    • https://bakotech.at/uploads/ckeditor/files/87503089541.pdfIn PDF document text
    • http://autolavaggiocraparotta.it/userfiles/files/15048682631.pdfIn PDF document text
    • https://lyonsinn.com/nbloom/fckuploads/file/wenajinutijaside.pdfIn PDF document text
    • http://richmore.kr/uploadfile/fckeditor/file/26786403273.pdfIn PDF document text
    • https://netcsemege.hu/ckfinder/userfiles/files/xifasivid.pdfIn PDF document text
    • http://duythuc-bearing.vn/uploads/userfiles/file/94272152646.pdfIn PDF document text
    • https://tndvn.com/js/ckfinder/userfiles/files/luxukesiburuv.pdfIn PDF document text
    • http://trevelsi.ru/ckfinder/userfiles/files/takojemivirodak.pdfIn PDF document text
    • http://fujieshubao.com/zk/UploadFile/file/2021090210052073499.pdfIn PDF document text
    • http://www.ih-consultant.com/ckfinder/userfiles/files/75347392491.pdfIn PDF document text
    • http://gibisch.biz/files/files/tiwabulebuvibenabilu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=cat+sim+online+mod+apkPDF link annotation
    • 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_off0000cb85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB85 19676 bytes
SHA-256: 375812b8d0cda78d0de7230740cbf55f94f29d2026193ed1cd004cc4d7ca4f91
font_01_sfnt_off0000ff42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF42 10576 bytes
SHA-256: 887813b3ee3d0d81432a9811b5c99be693be8cdf12d6bf222ee7577ad9523ebe
font_02_sfnt_off0001175e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1175E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1