Malicious PDF — malware analysis report

Static analysis result for SHA-256 d6dd391c8f0ac1ee…

MALICIOUS

PDF

101.1 KB Created: 2021-08-20 23:19:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 293b4f8383a48d60330250346ccd6bf5 SHA-1: 141590fb40a6dffb11470b3953e0eda2bff30f9e SHA-256: d6dd391c8f0ac1ee234ba6bf4cfecfe54471f98fd671893e52c0d86b83fd4b87
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 compromised CMS uploads or disposable hosting, forming a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery through these redirects. No scripts were extracted, and the document body was unreadable, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://syarmarka.ru/userfiles/files/jigupirep.pdf In PDF document text
    • http://bukharajohnscreek.com/sites/default/files/file/wubimotu.pdfIn PDF document text
    • http://cn-junsheng.com/upload/file///2021698665371.pdfIn PDF document text
    • http://saipanbooking.com/FileData/ckfinder/files/20210713_48FEEF5A3C4772D4.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608141949910b---10328331145.pdfIn PDF document text
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/rfijg9vd7tkcjvr7tm1vh4jh62/95562101160.pdfIn PDF document text
    • http://comicpapyrus.com/wp-content/plugins/super-forms/uploads/php/files/42fe8dfc550997eb39e1df812b51112c/55981449703.pdfIn PDF document text
    • http://unicaconsultoriarh.com/images/files/62997427815.pdfIn PDF document text
    • http://essuances.com/ckfinder/userfiles/files/3429934470.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/7deb2bd0fdebe9f09cbfc221e9c750c1/35018469480.pdfIn PDF document text
    • http://thangmayedex.com/webroot/img/files/19542542107.pdfIn PDF document text
    • https://almoheetmanpower.com/public_html/userfiles/file/49112044947.pdfIn PDF document text
    • https://zold-kommando.hu/files/60665463277.pdfIn PDF document text
    • https://eandjfamilyhealthcenter.com/wp-content/plugins/super-forms/uploads/php/files/9ca66adfc5e07aa5d4d4b3c728491adc/ravadufonanigi.pdfIn PDF document text
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d69f31453e9---20469584610.pdfIn PDF document text
    • http://onnetsolution.in/userfiles/file/bisajimojizomumopis.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/ejt0dugeshikeart8brokdt4h8/14126528831.pdfIn PDF document text
    • https://kcharp.com/ckfinder/userfiles/files/15862977698.pdfIn PDF document text
    • https://xn--bren-mgenwil-gcbf.ch/sites/default/files/fck-uploads/file/vonaroximudofimejev.pdfIn PDF document text
    • http://www.taylormadetc.com/siteadmin/ckfinder/userfiles/files/bugokiwijolirozuzutuxune.pdfIn PDF document text
    • http://heldermusic.nl/ckfinder/userfiles/files/4953114238.pdfIn PDF document text
    • http://omak1968.com/clients/71178/File/desirebumomaniv.pdfIn PDF document text
    • http://jvcc.cn/ckfinder/userfiles/files/210805035429801229obr9v.pdfIn PDF document text
    • http://myshopgroup.com/userfiles/files/53924669085.pdfIn PDF document text
    • https://fobiy.net/wp-content/plugins/super-forms/uploads/php/files/fbfab2979c641b8896e68c29ba078489/sabokinuzaxapejomamezosew.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=how+to+pass+nano+virus+on+plague+incPDF 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_off00012519.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12519 10792 bytes
SHA-256: b57eadfc8fadd3f1270c55dd0eb2313168facbafa721fc4a3b82cfafa5001e8f
font_01_sfnt_off00013e28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E28 17692 bytes
SHA-256: 9f3541e8eb586187956060cda28e55e72166a1d82af578aaa5a9c1111f77b3c9
font_02_sfnt_off00016c8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16C8F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1