Malicious PDF — malware analysis report

Static analysis result for SHA-256 43a93bd21a6e57eb…

MALICIOUS

PDF

82.0 KB Created: 2021-09-08 05:02:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6ce53b9628b6265c72ce20a890a55d40 SHA-1: 6f05a2e1d404f24ebd27318cf1082b92e10e8602 SHA-256: 43a93bd21a6e57ebb30d65449f50fec9376313e63e75e0233bab16dd835cbb50
156 Risk Score

Malware Insights

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

The sample was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to external websites, many of which are hosted on compromised CMS uploads or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 https://catamma.ru/uplcv?utm_term=the+stable+marriage+problem+structure+and+algorithms+pdf
    • http://arniestribu.com/campannas/file/67470396640.pdf
    • http://mjsolankifoundation.com/fck/imagesfile/4683673322.pdf
    • http://podlahypilat.cz/admin/file/takulopujofa.pdf
    • http://marinapogon.pl/upload/file/36786296327.pdf
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ce099884d3---kebonusupegi.pdf
    • http://cdn.eagle.mn/uploads/userfiles/files/25147131310.pdf
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/b8ed03dd26d6ae19ecbb1a1707fe4329/gafisumajorepef.pdf
    • http://ehhs1969.com/clients/6/67/67a0fa02f482ea8575b7cec7429e43a8/File/kefevavewabuzuj.pdf
    • https://stoneappeal.in/FCKeditor/file/56749869367.pdf
    • http://khachsanmyngoc.com/upload/files/14241119017.pdf
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609841fb96960---14858386233.pdf
    • http://oguzlarotomatiksanziman.com/depo/sayfaresim/file/gifodigikorepakoden.pdf
    • http://www.amedna.com/userfiles/files/66885434147.pdf
    • http://agcslohian.com/userfiles/file/dudaw.pdf
    • https://hopefor.today/wp-content/plugins/super-forms/uploads/php/files/14e731d1d2c6d473ecb22c7212d3d00f/ritijavegikofumetap.pdf
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160731a47d0aa3---wadifuduwekigujaroxobum.pdf
    • http://greenplanetnepal.com/userfiles/file/rekujapumomemogix.pdf
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/bkf4ngeut52vglip2immncp7mk/lologutelifaredilas.pdf
    • http://afghansolar.com/userfiles/file/37903035646.pdf
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfa5becc903---84695536554.pdf
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1609c68b6c8407---pazetopazurozimijepudig.pdf
    • https://mpksieradz.pl/upload/file/juboduleludotoradegapupo.pdf
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/1609ce08a558a8---7472313537.pdf
    • https://doxity.ro/ckfinder/userfiles/files/34075169486.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d77f.bin
8f4a74fe42a2d4e6379f35634ccbdbb44e519bf14fe82a82296357e17243a20c
pdf-font-stream PDF embedded font (sfnt) at offset 0xD77F 11268 bytes
font_01_sfnt_off0000f14c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF14C 16792 bytes
font_02_sfnt_off0001095e.bin
9708834faf0451cccc092b4aafa3f6cb536aae51bd218ad0589f8c832978ba5d
pdf-font-stream PDF embedded font (sfnt) at offset 0x1095E 18408 bytes