Malicious PDF — malware analysis report

Static analysis result for SHA-256 1f71588ba8cf8813…

MALICIOUS

PDF

96.0 KB Created: 2021-09-16 15:31:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4a8cd5edde2a4882c7f32237e6057205 SHA-1: 10cdd68da29b936727ad0fd489164c687e9f86f7 SHA-256: 1f71588ba8cf8813bf3dec75a7e5b63f859cfa0db9a688198a258f93d97cc036
164 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier indicating a high probability of malware. The file functions as a link farm, directing users to compromised CMS upload storage and disposable hosting sites, likely to facilitate the download of a secondary payload. The presence of a visual download button lure further supports the phishing and malware distribution intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://crewmak.ru/uplcv?utm_term=movie+download+from+torrentz2 PDF link annotation
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/161426b830b4f3---65493144190.pdfIn PDF document text
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/6a47989c52629825adb230a0858e7a45/jizuz.pdfIn PDF document text
    • http://taxplus.in/images/contentimages/files/54068908879.pdfIn PDF document text
    • http://geoass.eu/userfiles/files/45491336488.pdfIn PDF document text
    • https://maintogelonline2.org/contents/files/47811675975.pdfIn PDF document text
    • http://dylogistics.com/userData/board/file/dadipalikalogigozanujojiw.pdfIn PDF document text
    • http://tries.cz/media/images/upload/file/pufiruwowonakamejok.pdfIn PDF document text
    • http://fazendasaojudastadeu.net/fotosempresa/files/nowavavejelat.pdfIn PDF document text
    • https://butchercurnow.com/img/shop/contents/fevekinanurum.pdfIn PDF document text
    • http://travellerisland.com/files/25566762477.pdfIn PDF document text
    • http://ulv-fogger.ru/d/files/legujejezijuvo.pdfIn PDF document text
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/1e588d4256bd533c670bd8e91378cb8c/39949804840.pdfIn PDF document text
    • http://caminodesantiagoenmoto.com/assets/ckfinder/core/connector/php/uploads/files/jibajuroriruni.pdfIn PDF document text
    • http://foire-fromages-et-vins.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dad6001d82---rabuwani.pdfIn PDF document text
    • https://ssmahavidyalaya.org/lion/uploadedfiles/fck/files/file/gakozesesazekikin.pdfIn PDF document text
    • http://www.polni.si/Images/files/57938896329.pdfIn PDF document text
    • https://activepymes.com/pub/file/54649641980.pdfIn PDF document text
    • https://gionggiacam.gagiongvitgiong.com/ckfinder/userfiles/files/vipogaropikiwadita.pdfIn PDF document text
    • https://toscanafantastica.com/userfiles/file/zozuvugolutejoji.pdfIn PDF document text
    • http://www.smwiarus.pl/ckfinder/userfiles/files/50273162106.pdfIn PDF document text
    • http://maivietnamesecotati.com/uploads/files/sorururulen.pdfIn PDF document text
    • http://jump360.co/upload/files/20210914082844.pdfIn PDF document text
    • 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_off000114a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114A2 17460 bytes
SHA-256: 54c6847edfa841c2bd92976ff1f95ec4a26a923bb8d121b07eb8a0148b356532
font_01_sfnt_off000141f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x141F8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015a0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15A0F 10672 bytes
SHA-256: 8a03ba4d74d7e765d8223ef095e7f3d25189d1d0e210800fafc86f89942dddf0