Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d334a4f1c06f6e2…

MALICIOUS

PDF

80.7 KB Created: 2021-09-19 10:55:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 06836690ca3d7f47c74ad7afd8e8dbd3 SHA-1: e6efadf7124643c123095fb45552c553ab096e83 SHA-256: 4d334a4f1c06f6e23ec01a600ec6205f98c382890d3e89afdef5b9412b8ae21f
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to external resources, many of which are hosted on compromised WordPress sites, suggesting a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the PDF structure itself facilitates the attack by hosting links to further malicious PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 7

  • 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.
  • 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://coretry.ru/uplcv?utm_term=the+relaxation+and+stress+reduction+workbook+free+pdf
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/1613c75a8912eb---loritoku.pdf
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613e77bf82811---95802079139.pdf
    • https://loyd.rs/images/file/karulolapupivupevopelar.pdf
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613871dd94d27---kunonaligijebofijuto.pdf
    • http://gryfarmerskie.pl/pliki_wyswig/files/68231484645.pdf
    • http://gzhangqin.com/uploadfile/files/75536751239.pdf
    • http://heimundsicherheit.de/userfiles/file/kujofejogukapumowofave.pdf
    • http://lucidarepavimentimarmogenovaealessandria.it/userfiles/files/zulajojowupuxijunoxu.pdf
    • http://xn--939a66v0zjo3bcvdmrp.com/data/ckfinder/files/zinomumuduzu.pdf
    • http://transportdiverse.com/uploads/files/suxuzezukopir.pdf
    • http://thegioituigiay.net/uploads/files/luxotawigemasinurosozim.pdf
    • https://poganyvolgyi.hu/userfiles/file/45287402478.pdf
    • https://laplacedesstores.com/upload/file/jixopazizolifo.pdf
    • http://mtegl.wsystem.sk/userfiles/files/numaribeto.pdf
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c3155800c3---fukapepu.pdf
    • http://mg001.cn/upload_fck/file/2021-9-11/20210911095354997296.pdf
    • https://tour-paris-guide.com/cite_imgs/file/sakalizexes.pdf
    • http://brixtontaxi.com/survey/userfiles/files/14319780790.pdf
    • https://www.spitalmoldovanoua.ro/ckfinder/userfiles/files/vaxaronuzeti.pdf
    • http://oguzlarotomatiksanziman.com/depo/sayfaresim/file/jesaju.pdf
    • http://ty6600.com/userfiles/file/69088257003.pdf
    • https://propertiproperty.com/Uploads/userfiles/files/46067205515.pdf
    • https://suacuachuyennghiep.com/uploads/files/43088390638.pdf
    • http://sushibelovo.ru/files/lebumituvo.pdf
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/16130eb66eb368---15836977754.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d68d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD68D 16792 bytes
font_01_sfnt_off0000eea4.bin
491e35f45d8e2c29ab674c44314b3c12b24728581b54e5fb4d4450c4d90352b8
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEA4 11200 bytes
font_02_sfnt_off000108a9.bin
744d826d41b87ce8e21d79b7eb0b08433f4ccfaf0d67e30d35f35ffdb5d2951d
pdf-font-stream PDF embedded font (sfnt) at offset 0x108A9 17188 bytes