Malicious PDF — malware analysis report

Static analysis result for SHA-256 633b5acb5a356bac…

MALICIOUS

PDF

90.8 KB Created: 2021-09-09 04:59:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a71539fec2f56e8c27d979918c7679c6 SHA-1: d9d97932fc7ac03dcb3017bc5fa7e8c67bda87bd SHA-256: 633b5acb5a356bac138eaa22402452eedec81ccbeae9162c6c6284aa6e2b77f4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links, many of which point to other PDF files hosted on compromised websites or disposable domains, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery through these linked documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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
  • 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://palet-school.com/files/files/29230314762.pdf In PDF document text
    • https://mgs-on-track.com/app/webroot/userfiles/file/galexelelori.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/7303f16d0e44e602bc51c57c61e68185/67920936575.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/161334672d150d---dagarutuzep.pdfIn PDF document text
    • http://www.predia.cz/userfiles/file/xovuxitawebubajinogu.pdfIn PDF document text
    • http://orem.mn/uploads/files/votunevoxan.pdfIn PDF document text
    • https://christianbelieversmatrimony.com/web/christiansbelieversmatrimony/photos/ckeditor/files/jonazeweturosezuravirugik.pdfIn PDF document text
    • https://valerart.com/ckfinder/userfiles/files/17898691547.pdfIn PDF document text
    • http://schokofontaenen.de/idata/89106489091.pdfIn PDF document text
    • http://orel-trinity.ru/sites/default/files/file/dinib.pdfIn PDF document text
    • http://benthanhsgfarm.net/images/uploads/files/73917429287.pdfIn PDF document text
    • https://www.almuhja.com/ckfinder/userfiles/files/tasaxaxixalufofadidi.pdfIn PDF document text
    • http://tdbm.vn/upload/files/gawitixotag.pdfIn PDF document text
    • http://loscogliodifavignana.it/userfiles/files/54786473317.pdfIn PDF document text
    • https://onderhoudnlgarantie.nl/upload/file/82525240694.pdfIn PDF document text
    • http://autodilykanka.cz/cmsimple/images/file/jukupafamaz.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/161335c860e4cb---defekorajiladidopi.pdfIn PDF document text
    • http://okfilm.kr/userData/board/file/zorixivazovukumaga.pdfIn PDF document text
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134cf3100c3d---rifupujovodumozaw.pdfIn PDF document text
    • http://ark-mr.com/data/home/qxu2063190031/htdocs/uploadfile/files/jilosoluzuxilupu.pdfIn PDF document text
    • http://qdsenfeng.com/data/files/42309341048.pdfIn PDF document text
    • https://armature.ir/cache/fck_files/file/zezurem.pdfIn PDF document text
    • http://geonatlife.es/ckfinder/userfiles/files/bereduzufukapogosulil.pdfIn PDF document text
    • https://cuatudongbinhduong.net/uploads/files/lexagomamenisigosabedi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=popular+movie+appPDF 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_off00010286.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10286 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011a9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A9D 10208 bytes
SHA-256: ee33632a45822a878b3a9f43cb020285805b88a8917ddac87274e2320c4d7d0c
font_02_sfnt_off00013180.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13180 17228 bytes
SHA-256: a064652ec849dae514dfeb4e4bd92ccceabe1583ad62bfecc8c806d090db45d3