Malicious PDF — malware analysis report

Static analysis result for SHA-256 31a456b3f05ba168…

MALICIOUS

PDF

89.1 KB Created: 2021-07-23 09:53:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: f36da23a7473753a6276aa36ac4c1e1d SHA-1: 1888def824985742a208d95d2e559d2f5a6c8597 SHA-256: 31a456b3f05ba16879b434ec67cb023e7d14b823f41f6bad8be694f177804c2d
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS upload directories, indicating a potential phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were extracted, the structure and URL findings point towards a link farm used for initial access, likely via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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 http://zetrade.cz/userfiles/file/nogabetupesojezevorifu.pdf In PDF document text
    • http://kolaykanal.com/userfiles/files/xarapebazijajawe.pdfIn PDF document text
    • http://jullien38.com/ressource/site-image/files/73407845909.pdfIn PDF document text
    • http://ingenermarket.ru/userfiles/pimamajixozisiregexewunig.pdfIn PDF document text
    • http://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608112d401d2f---filujojosop.pdfIn PDF document text
    • http://auapp.ch/userfiles/files/81315484736.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/iu843fkiqd05sdgl81fk55lrp6/wuwutiberisafimoboruder.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16080a16cd2888---35453834629.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094dfa5423ba---48551861301.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/7ed66bf14306e664ccf953865f6d7523/xugilenubimi.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1608f73a90d1f0---80808078038.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba3d155932d---gejasigalinigidilo.pdfIn PDF document text
    • http://studiofranzoni.eu/userfiles/files/gokimetise.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160db1af322c14---delerumizoxanezudiw.pdfIn PDF document text
    • http://hhcreunion.com/clients/4/43/43f38dc94a4d709fe78decf5bd9d7370/File/fumavenumok.pdfIn PDF document text
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/160948930214ee---18818081024.pdfIn PDF document text
    • http://kavtas.com/images_upload/files/8356183574.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/16070bb2b97c58---logigaterilodunamasuvata.pdfIn PDF document text
    • https://uleiuri.ro/userfiles/file/17776200881.pdfIn PDF document text
    • https://www.lightingsolutionsinc.net/wp-content/plugins/super-forms/uploads/php/files/fd8facf48331015dfba474b563b5676e/zitodu.pdfIn PDF document text
    • http://asupuro.com/user_data/image//file/83750096595.pdfIn PDF document text
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/298755bfa9eaa5a35ea60b5e3a9378a5/51208732128.pdfIn PDF document text
    • https://mfdesign.hu/files/file/pujesituniwa.pdfIn PDF document text
    • https://uppersanduskyrotary.com/cms/files/File/23348851213.pdfIn PDF document text
    • http://pwr-tech.ru/userfiles/file/18686941783.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=congruent+triangles+in+a+parallelogramPDF 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_off0000f101.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF101 10728 bytes
SHA-256: d80a8b7c286e69778a4ad39407bfddba4edf8e2208fff9b357fba0df0ef7c84b
font_01_sfnt_off000109b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109B0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000121c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121C2 19692 bytes
SHA-256: 447f753174ce9e421f5f0f1eb85d3b11a903ce6bdd769761d0a0c0a2a11dc6f9