Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef072492787a9f97…

MALICIOUS

PDF

68.9 KB Created: 2021-10-03 11:42:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 597e0c9b77bad65e6d91580c713063cb SHA-1: c392837f7e93b3060839121009329d7c82b0c0f9 SHA-256: ef072492787a9f974c9d6c9ece146fc915ad12618d7262861faeb4976ad587ca
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to external sites hosted on compromised CMS uploads or disposable domains, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable, so the rationale is based on the URL analysis and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 http://hasdeu.md/data/userfiles/files/loxogerewaboj.pdf In PDF document text
    • http://dj-maily.com/uploads/pages/files/wolalunupozosebotipibasi.pdfIn PDF document text
    • http://tatishev.ru/admin/ckfinder/userfiles/files/vonixuvitukugupomujof.pdfIn PDF document text
    • https://qud27rxl1-k61l.com/contents/files/62848511308.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16147089d22715---77228946441.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/16152911808981---23751200410.pdfIn PDF document text
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16159336bbf012---zenapevekobiva.pdfIn PDF document text
    • http://www.saito-ken.jp/userdata/file/fatowikujipuwid.pdfIn PDF document text
    • https://roadtoring.com/wp-content/plugins/super-forms/uploads/php/files/aaaa118610775d342f76390f9031943d/negunefugewade.pdfIn PDF document text
    • https://ises.ca/phpsites/vertical_living/uploads/file/nofuxekirajez.pdfIn PDF document text
    • http://cuspsurgeons.com/userfiles/file/67058207342.pdfIn PDF document text
    • http://lpxs168.com/filespath/files/20210918185823.pdfIn PDF document text
    • https://edu-mate.kr/_UploadFile/Images/file/lezusimeba.pdfIn PDF document text
    • http://phaptangpgvn.net/app/webroot/upload/files/fifomumejupujizute.pdfIn PDF document text
    • http://weiddy.com/uploads/files/202109090619392249.pdfIn PDF document text
    • http://dkyangmei.com/uploadfile/file/2021100109330673499.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/161338874ac0ee---55839291612.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161542e555ebfc---fuzokinowibepezeraje.pdfIn PDF document text
    • https://inprovitparaguay.com/ckfinder/userfiles/files/nuwuxiduk.pdfIn PDF document text
    • https://www.bakkersvlaanderen.be/resources/plugins/ckfinder/userfiles/0/files/xawalikir.pdfIn PDF document text
    • http://7seapharmtech.com/Uploadfiles/files/29877721972.pdfIn PDF document text
    • http://buffagiuseppeinfissi.com/userfiles/files/58913751342.pdfIn PDF document text
    • http://nilesk.com/userfiles/file/97723348896.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=lion+sequence+yogaPDF 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_off0000b1c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1C9 14672 bytes
SHA-256: 7de1c12ce5d6ea7bfbfc798191221ac0233287fe7b00d7e2eae46528d161a678
font_01_sfnt_off0000d674.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD674 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ee8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE8B 10480 bytes
SHA-256: bda875f132b9023eb71bcdb8cce12749f07a09ceb728bb9e1c2ff9a48595848e