Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9d89e3680aedc73…

MALICIOUS

PDF

75.2 KB Created: 2021-09-18 15:49:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: a2232213077f711731d5a44cc1514692 SHA-1: 4d71ddf7df0d899602654fbada9d08d7884f4873 SHA-256: a9d89e3680aedc7356a9e40c704d9f96a48b67ebe90e69fea26faa16510bf4da
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links to compromised WordPress sites and other disposable hosting, indicating it functions as a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or distributing further malware. The file's structure and embedded URLs align with techniques used to redirect users to malicious content.

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://www.oasipizza.it/wp-content/plugins/formcraft/file-upload/server/content/files/161321c1e90e96---99870438579.pdf In PDF document text
    • http://cgmorenanews.com.br/ckfinder/userfiles/files/sanebi.pdfIn PDF document text
    • http://bertrandetgastineaudesigners.fr/userfiles/file/fosibagevedanizorekok.pdfIn PDF document text
    • https://confidence-ist.mktechsol.com/ckfinder/userfiles/files/fimusulovusifenevek.pdfIn PDF document text
    • http://www.teaterskolen-efteruddannelsen.dk/ckfinder/userfiles/files/wuzukesejidukusufokajez.pdfIn PDF document text
    • http://olynskiconstruction.com/pics/file/zezibasuvas.pdfIn PDF document text
    • https://cedria.es/DOCUMENTS/FotosFCKEditor/file/85344720472.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/7e12b1644b224a5a8bd79131ec12b570/kobajaxoletezinexigajun.pdfIn PDF document text
    • http://fernandopelosini.it/userfiles/files/96287545598.pdfIn PDF document text
    • http://kabaretyimpresariat.pl/Upload/file/2059108628.pdfIn PDF document text
    • https://hitourkorea.com/FileData/ckfinder/files/20210904_A446261D762E8737.pdfIn PDF document text
    • http://a-b-i-s.net/layout/bilder/file/53401503754.pdfIn PDF document text
    • https://sharmtocairo.com/userfiles/files/xudisumalivizaleti.pdfIn PDF document text
    • http://fmi.lu/userfiles/files/40968650688.pdfIn PDF document text
    • http://emilygrilltogo.com/uploads/files/93201089301.pdfIn PDF document text
    • http://albertf.madteam.net/ckfinder/userfiles/files/vanipofaran.pdfIn PDF document text
    • http://havefuntogether.com/image/upload/File/63835984587.pdfIn PDF document text
    • http://domadoma.cz/userfiles/file/mixipuzotukenatorusi.pdfIn PDF document text
    • http://profisystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16130d8c3efa82---xeritafawusukadip.pdfIn PDF document text
    • http://anhuishangbiao.com/upload_fck/file/2021-9-6/20210906011143605042.pdfIn PDF document text
    • http://szamosiszerviz.hu/feltoltott/files/21570433726.pdfIn PDF document text
    • http://rc-modeller.se/images/file///46013174696.pdfIn PDF document text
    • http://dietetyka-24.pl/images/files/78458060865.pdfIn PDF document text
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134cebd135fe---8293674118.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=line+color+3d+game+downloadPDF 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_off0000bf22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF22 10664 bytes
SHA-256: 124cb941d1e4483649450c3aa17d455d6fb33698ff8693ee8131d739fbc8069d
font_01_sfnt_off0000d75a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD75A 18308 bytes
SHA-256: 434ee674ba4e22a252fa27b1bff9a9107894f11ddd398fcffc894848a354340a
font_02_sfnt_off00010753.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10753 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1