Malicious PDF — malware analysis report

Static analysis result for SHA-256 28fe3ed87304d34d…

MALICIOUS

PDF

82.9 KB Created: 2021-09-10 06:51:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 0b8935d9be6bbc3a38d3524bc595bd73 SHA-1: e88f9a2816a91b01cde386524c086deb7c8fdd62 SHA-256: 28fe3ed87304d34d44c62b5edd5c2b66c8aef09df840b0629d75e22a5860d413
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised CMS upload storage and disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://posaonakosovu.com/ckfinder/userfiles/files/25917479889.pdf In PDF document text
    • https://watfordfairtrade.org/app/webroot/img/files/xalabazavixusovosen.pdfIn PDF document text
    • https://tadimtursu.com/image/files/77575649972.pdfIn PDF document text
    • https://sklepbonus.pl/userfiles/file/23017557375.pdfIn PDF document text
    • http://haphadoor.com/upload/files/nulemefanakigumu.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/16134a1be3c5fb---522090153.pdfIn PDF document text
    • https://pierrelemagicien.com/userfiles/file/tevapotolivud.pdfIn PDF document text
    • http://jcon-aps.dk/userfiles/file/77760848510.pdfIn PDF document text
    • https://www.jnvhardoi.org/ckfinder/userfiles/files/pixikutozanuzijilifidabu.pdfIn PDF document text
    • http://prestinoequitacion.com/imagenes/upload/files/54198509129.pdfIn PDF document text
    • http://onlinecommerce.bg/uploads/pages/files/98897653670.pdfIn PDF document text
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a912012ad7---28966878518.pdfIn PDF document text
    • http://dongshengcable.com/images/upload/File/5686856221.pdfIn PDF document text
    • http://velocimapper.com/webfiles/file/12212017590.pdfIn PDF document text
    • http://www.espaciocultivarte.com/ckfinder/userfiles/files/38315113316.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16134c479cdf59---97373889521.pdfIn PDF document text
    • https://studybrilliant.online/app/webroot/img/userfiles/file/7855440750.pdfIn PDF document text
    • https://alves.bg/ckfinder/userfiles/files/39529095474.pdfIn PDF document text
    • http://wx-test.com/upload/ckimg/files/202109091846053037.pdfIn PDF document text
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613aa2200799d---kuriderovosuf.pdfIn PDF document text
    • https://siphouse96.com/wp-content/plugins/super-forms/uploads/php/files/f7572e8de0b8de95a423be9b1086104e/14068895764.pdfIn PDF document text
    • http://elektro-galerie-hamburg.de/userfiles/file/sikiwowojaxatesivafifovo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=pokemon+multiverse+apk+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_off0000dd22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD22 10896 bytes
SHA-256: dde1e48259fcdfc43876488e2b72dd45ec9478e14072f5d33e56fb51e4558953
font_01_sfnt_off0000f66a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF66A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010e7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E7C 18888 bytes
SHA-256: f230d4013310ac382117335b45baed526111db436491dc3ca9d0c12a3899e3f8