Malicious PDF — malware analysis report

Static analysis result for SHA-256 c23f4c71d306c150…

MALICIOUS

PDF

75.1 KB Created: 2021-09-17 03:49:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 9f425836edd296fb53d3c616111daa5a SHA-1: 7d7df67f8e1a0983008884d934b72c9f9ee2a647 SHA-256: c23f4c71d306c150db57ab355e2e8f623ca388368a8fdb832e4a7c023d79a4c8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories, suggesting an attempt to host or distribute malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery via these links. No scripts were extracted, but the PDF structure itself is used to facilitate the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://coretry.ru/uplcv?utm_term=apk+gta+v5 PDF link annotation
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/424ae78ff94d784020a085a23f29e8f5/vadisijatededagori.pdfIn PDF document text
    • https://cosonnguyenthanh.vn/webroot/userfiles/files/53694643377.pdfIn PDF document text
    • http://restauraceeverest.cz/userfiles/file/nopabapopataxet.pdfIn PDF document text
    • http://uralinteh.com/uploads/files/lopodifizi.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/161320bae3d311---xofatudosuru.pdfIn PDF document text
    • http://skipjackpoke.com/ckfinder/userfiles/files/63177485429.pdfIn PDF document text
    • http://burelomdo.com/ckfinder/userfiles/files/netaso.pdfIn PDF document text
    • http://elsped.hu/files/file/ruvumifalijirepatefu.pdfIn PDF document text
    • https://vico-real-estate.com/ckfinder/userfiles/files/60874264783.pdfIn PDF document text
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/hq37okcp3dokflt9gird0pvh6d/15032338834.pdfIn PDF document text
    • http://kmconlinecme.com/userfiles/file/ripuno.pdfIn PDF document text
    • http://111-orte.de/testarea/cwsCMSlight/media/files/39315201582.pdfIn PDF document text
    • https://cmfnepal.org/userfiles/files/panoxovugazomewuxa.pdfIn PDF document text
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/d93f61c441a8adb3ad3a5ca9bf67ad38/jodagepokotetel.pdfIn PDF document text
    • https://jyapa.com/jhuoyue/uploadfiles/losomifuwazaku.pdfIn PDF document text
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/db65d64f5ad3104d57972e9f049b0d9b/46284831507.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130acdab6021---21588298514.pdfIn PDF document text
    • https://bakwanudang.com/contents/files/nulilagagazigukebuki.pdfIn PDF document text
    • http://ahnil.com/userData/board/file/bafabuwepilalufufula.pdfIn PDF document text
    • https://curtain.jinware.com/upload/files/30481998194.pdfIn PDF document text
    • http://federicozucchettiarchitetto.eu/userfiles/files/64464741596.pdfIn PDF document text
    • http://tv-kitchen.ru/files/files/kizojutelekegobowuw.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_off0000c505.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC505 17160 bytes
SHA-256: 94d84849022dfa152dc2be867567f2bbd095a4ce6c797f13066baf8dcbed6094
font_01_sfnt_off0000f0ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0CA 9940 bytes
SHA-256: 873607a057ca50387f9525903654044402aadd9ce826120e9040b51b020547c0
font_02_sfnt_off00010701.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10701 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1