Malicious PDF — malware analysis report

Static analysis result for SHA-256 d553c2412392db10…

MALICIOUS

PDF

85.6 KB Created: 2021-07-02 23:42:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 143664e7c2ae21ad336c8514609afc7c SHA-1: 8e5f27b86aed77e5eea62c3540f9a50f6ef24ba3 SHA-256: d553c2412392db10d981b283a199570dd0c25bdc947e9957e84820b9df42ed50
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm with multiple URLs pointing to other PDF files hosted on compromised WordPress sites. This suggests a tactic to distribute malicious content or redirect users to phishing pages. The ML classifier strongly indicated maliciousness, and the presence of numerous external links supports a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 5

  • 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://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/f9318f7fe2959a34400ee99e244fa192/99473710018.pdf In PDF document text
    • http://wittlich-luexem.de/userfiles/file/wotukotapulaguwajit.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/opgap38jilmb7u3c0nl2strth2/barejalapojonekemiki.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087fe42afa29---66396027227.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/46edf57c8f6f2db4cac2d050834cb4af/bukavave.pdfIn PDF document text
    • http://interiorconsignments.com/media/file/pixovi.pdfIn PDF document text
    • http://atdawnwelift.com/userfiles/file/65010601122.pdfIn PDF document text
    • http://kraski-chernila.ru/resources/file/20896005938.pdfIn PDF document text
    • http://animalscipublisher.com/files/upfiles/file/74702487956.pdfIn PDF document text
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e1294417b2---lojizutufip.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16075bdf986163---sunuzibole.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/l0mev6lbp80gt4642ss5fc7v2a/67603666592.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c42f5e0454f---69870008017.pdfIn PDF document text
    • http://podlahyadvere.sk/editor_uploads/system/files/77181961468.pdfIn PDF document text
    • https://bf-pomosch.ru/wp-content/plugins/super-forms/uploads/php/files/e2a5d2fauuan17rve27ioql4g0/61628866001.pdfIn PDF document text
    • http://www.gaviprintpack.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087525b85bff---gofelurulowuwofefifeb.pdfIn PDF document text
    • https://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/fc5cc91e96f12d1d9df61873120d5fa3/26075239275.pdfIn PDF document text
    • https://prsnashville.com/wp-content/plugins/super-forms/uploads/php/files/3ef9fd6337623a7c3ec8beee8776b4d0/fupege.pdfIn PDF document text
    • https://pensiuneavalentina.ro/app/webroot/file/77097041013.pdfIn PDF document text
    • http://timandlor.com/userfiles/file/76913217610.pdfIn PDF document text
    • http://klimagra.pl/images/wysiwyg_img/file/10839933777.pdfIn PDF document text
    • https://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/fc77ed06761bb45c3864c31093b1c71f/kapakuvowelelulal.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=puzzle+complex+cross+numbers+answersPDF 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_off0000ea63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA63 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001027a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1027A 10836 bytes
SHA-256: c8dc357826058d24e6e23d71fd4944208abbf9fac812fd8ddc4c08456e2ff47c
font_02_sfnt_off00011b5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B5D 17500 bytes
SHA-256: 2171d84a9410331693bc6cbcab92ae6c5bf7fcae9b9031fc6cfbb8215f5ad48e