Malicious PDF — malware analysis report

Static analysis result for SHA-256 ce656b3ccabb85ea…

MALICIOUS

PDF

82.2 KB Created: 2021-09-11 17:07:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 91b1d283aa43f822045c7c89367f9153 SHA-1: 2df6edfeb4bcec21d3235a29ed71b2ee30a30ed1 SHA-256: ce656b3ccabb85ea65b8863c36449d90b923b5d8c57b6e104156d856adc850b0
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous external links, with one heuristic specifically identifying it as a link farm on disposable hosting, suggesting a phishing or redirection scheme. Although no scripts were explicitly extracted, the presence of PDF_URI and EMBEDDED_URL heuristics points to the document's function of directing users to external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 5

  • 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.
  • 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://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613031766afd5---91752278700.pdf In PDF document text
    • http://ukrainski-rosyjski.pl/userfiles/file/91241034044.pdfIn PDF document text
    • https://ruiguoex.com/upfile/files/2021/09/04/62565800869.pdfIn PDF document text
    • https://dalilak1.com/userfiles/file/fogupujatifilefexug.pdfIn PDF document text
    • http://tsmsaldature.it/userfiles/files/95645515906.pdfIn PDF document text
    • http://tokyosushilohaus.com/uploads/files/rokufadu.pdfIn PDF document text
    • https://vnjhanoi.com/upload/files/38567959127.pdfIn PDF document text
    • http://csim.jp/ckeditor/uploads/files/zimudisa.pdfIn PDF document text
    • http://www.leasebridge.com/CKUPimg/files/nuroginisusasowopidokes.pdfIn PDF document text
    • http://mecateengenharia.com.br/ckfinder/userfiles/files/jozasulanid.pdfIn PDF document text
    • http://dioceseofniranam.org/userfiles/file/42244453459.pdfIn PDF document text
    • http://talcmanagement.com/uploaded_files/userfiles/files/7362769641.pdfIn PDF document text
    • http://apexibd.com/uploads/fck_uploads/file/gumizijexujapofet.pdfIn PDF document text
    • https://travelinnsuites.com/nbloom/fckuploads/file/rubosidikavisak.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137f3a882da9---xubedotaw.pdfIn PDF document text
    • http://akvatoria.by/UserFiles/files/duwiligebuzomabotu.pdfIn PDF document text
    • http://confidence-ist.com/ckfinder/userfiles/files/37490330353.pdfIn PDF document text
    • http://oembag.com/uploads/files/202109050625309006.pdfIn PDF document text
    • http://gaytonfa.com/upload/files/78587677846.pdfIn PDF document text
    • http://bowie.abwingsmd.com/uploads/files/39031859242.pdfIn PDF document text
    • https://krassimirtaskov.com/userfiles/files/bitavunajogejileg.pdfIn PDF document text
    • https://westhygiene.hu/editor_up/96895131815.pdfIn PDF document text
    • http://sjhrz.com/images/upload/File/zageruresulivepexefogorux.pdfIn PDF document text
    • https://kalashad.com/userfiles/file/89169541092.pdfIn PDF document text
    • http://kortennis.co.kr/B/ck/ckfinder/userfiles/files/panugefejomiga.pdfIn PDF document text
    • http://dongphat.net/upload/files/27796554080.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=pdf+giant+18PDF 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_off0000df11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF11 17320 bytes
SHA-256: 11db231c2c250395129a8834252fdafad6dfcc64629af21b6391c4929a3ae723
font_01_sfnt_off00010c07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C07 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001241e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1241E 10224 bytes
SHA-256: d8b30d9d1a03c03f331f56a39308e7d95832b465555bee8891e41950eb0a7d2a