Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a71cebb7f1905ec…

MALICIOUS

PDF

69.2 KB Created: 2021-09-18 08:55:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 95d920debe8ffddc17a241010c89904c SHA-1: 1375fbba16746587606c7fee69372019fade148b SHA-256: 9a71cebb7f1905ec18918273b9f47eefd3c8a4c75939716569697744a3566a2f
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple domains, many of which are hosted on compromised CMS upload storage or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing sites or download further malware. No scripts were extracted, but the embedded URLs and heuristic firings are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://www.lukoilmarine.com/ckfinder/userfiles/files/77513209416.pdf In PDF document text
    • http://all-premium.com/user_file/files/dusitarevaja.pdfIn PDF document text
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/45b57ad6a8bc8248a77853c65cc29339/31674752284.pdfIn PDF document text
    • http://thaifilmind.com/UserFiles/file/likabebumib.pdfIn PDF document text
    • http://maxbrio.kr/files/files/46350492620.pdfIn PDF document text
    • http://cnzhongkui.com/fckeditor/editor/filemanager/connectors/php/uploads/file/101126009280.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/e1234f64744dcf34498c7635f4688c82/zexuvazuxagenematatalini.pdfIn PDF document text
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/16140bae672011---biputuzaruk.pdfIn PDF document text
    • http://1carl.com/userfiles/file/ligunujijajoporonize.pdfIn PDF document text
    • http://incomingmakedonia.com/files/files/66979954462.pdfIn PDF document text
    • http://sumtinathholidays.com/admin/uploadfiles/file/gatovoxuwusovatobitawi.pdfIn PDF document text
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16135af2743351---sipumevo.pdfIn PDF document text
    • http://lacasedescaraibes.fr/file/ratobopovuxa.pdfIn PDF document text
    • http://coral-travel66.ru/admin/ckfinder/userfiles/files/99372072111.pdfIn PDF document text
    • http://csa.china-led.net/static/editor/ckeditor/ckfinder/upfile/files/57759723982.pdfIn PDF document text
    • https://www.renfrewareahealthvillage.ca/ckfinder/userfiles/files/38485555346.pdfIn PDF document text
    • https://thaiahpa.com/flash/files/30460066044.pdfIn PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161416cd449a4d---4829403190.pdfIn PDF document text
    • http://bridgestone-ice-cruiser-7000.ru/ckfinder/userfiles/files/26774796180.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613635069041e---lolufekufejefisumuxuval.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/161408ac7ad31e---jasusonixowaput.pdfIn PDF document text
    • https://corpusbg.com/files/fck/file/56911164302.pdfIn PDF document text
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/161401d6cb161e---zupanujorakekowetege.pdfIn PDF document text
    • http://radiopoint.cz/userfiles/file/mepezizido.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=download+6lack+album+freePDF 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_off0000b146.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB146 10868 bytes
SHA-256: 68db4e0c8112f39cc048cbbb66047983b6aaec3953d87f1b52c7041df12a6052
font_01_sfnt_off0000ca6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA6D 14716 bytes
SHA-256: 7b77d4c4196d79927d95a119433e708252af0fa862d05bcafc724b3cdcfeace9
font_02_sfnt_off0000ef91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF91 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1