Malicious PDF — malware analysis report

Static analysis result for SHA-256 a35733791b4402f7…

MALICIOUS

PDF

94.9 KB Created: 2021-07-01 11:23:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: af95149e2d351b9b89602fbea7448995 SHA-1: b39fd21adebc2d801c946be6bf3e895707fbf8d5 SHA-256: a35733791b4402f70809a5dff4716f18865dc3128c646e0ca0e1513e63b37926
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised WordPress sites, suggesting a phishing or malicious redirection attempt. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to lure users to malicious content or exploit vulnerabilities. The file's structure as a link farm on disposable hosting further supports a malicious purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9941

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://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086843186dbf---xanewu.pdf In PDF document text
    • https://utilitydiscount.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087d3d39091d---delagipevutaw.pdfIn PDF document text
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cd0eaa3de7---penimulasawokop.pdfIn PDF document text
    • http://ahdongjiu.com/upload_fck/file/2021-5-4/20210504192045223708.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a938b258546---35947249248.pdfIn PDF document text
    • https://noddy.nu/images/file/gefulodaxunupokiselefo.pdfIn PDF document text
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160845cf581b39---noluzujedu.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160837bf715b46---wajixagusuzakodewini.pdfIn PDF document text
    • http://kraski-chernila.ru/resources/file/97983978913.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/d4258d49b751de7a096bf7ef2f607f08/47702549226.pdfIn PDF document text
    • http://www.suffaheducation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080a1730b948---72771484472.pdfIn PDF document text
    • http://aiswaryamatrimonials.com/fck_uploads/file/wixixataguni.pdfIn PDF document text
    • http://densayhongngoai.com/uploads/userfiles/file/45601941095.pdfIn PDF document text
    • http://symbioticlifetech.org/attfile/fckimg/file///2021051085728_62337704.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607434305f94b---88113526432.pdfIn PDF document text
    • https://burgaseguros.com/userfiles/file/50157234774.pdfIn PDF document text
    • https://workinhotel.com/upload/fckfile/60696337445.pdfIn PDF document text
    • http://abnicum.com/files/file/69231294216.pdfIn PDF document text
    • https://thieumaunao.vn/workspace/develop/uploads/ck_upload/files/160568210.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/48db2b032a0d0d9cab16e28bef20e2fe/35068059088.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/rpe2fidhcc1d95g6gnh977a3m3/55631287083.pdfIn PDF document text
    • https://www.eziblank.com/wp-content/plugins/super-forms/uploads/php/files/669t2qeosqpmpna9990efd2s65/nomisekobovokiduma.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=telescoping+series+partial+fractionsPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f7d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7D3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010fe4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FE4 16084 bytes
SHA-256: 325c5f5cda05429ae92d15c23118ca1b8712e485108c584e1e30b0ff615913b7
font_02_sfnt_off00012511.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12511 10620 bytes
SHA-256: 0d09389accbe4f0d5235cb84f46d42a1c9c22bbb83fd04464eaaacfca717aad6
font_03_sfnt_off00013d82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D82 18076 bytes
SHA-256: db527e41c5ea37e90b80b3987c58c459a45223e1c100c92ec9a8d73df65fe770