Malicious PDF — malware analysis report

Static analysis result for SHA-256 fc4d2b8359fa080a…

MALICIOUS

PDF

88.6 KB Created: 2021-06-28 09:36:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: acbef220c90a45dd8a7744a946c30ff3 SHA-1: 9b15c62830826522184182bc41aebe3d009a8982 SHA-256: fc4d2b8359fa080ac0c87a32526fcba2b314fdece2822ae3d310a4f01b2996a2
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a link farm that directs users to multiple distinct hosts, many of which appear to be compromised WordPress sites. These sites are hosting further PDF documents, suggesting a multi-stage redirection or download process. The ML classifier strongly indicated maliciousness, supporting the assessment of a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160925434b3772---fepipiwi.pdf In PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/1609c9d17300a5---mafobipizugedugopodepajif.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/160884080d2639---7326826769.pdfIn PDF document text
    • http://xn--42-6kcdlkbomh7beggito5p.xn--p1ai/userfiles/file/79841509470.pdfIn PDF document text
    • https://designclarf.it/file/64465467596.pdfIn PDF document text
    • https://signaturetowerpune.com/wp-content/plugins/super-forms/uploads/php/files/lnk8k0r13jr8knev83h16t6m66/95810884415.pdfIn PDF document text
    • https://zivotzaokny.eu/res/file/3393639405.pdfIn PDF document text
    • http://macautemple.com/userfiles/file/memewuneduzefaxobe.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160856cf6ed0b6---nexozeja.pdfIn PDF document text
    • http://springswellness.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606c946c0d082---72238216037.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cb9c82a36e---54539754734.pdfIn PDF document text
    • https://otartufo.com/ckfinder/tartufofiles/files/bazazatiwixafigarux.pdfIn PDF document text
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5e3eba73a0---42065831417.pdfIn PDF document text
    • https://anmimar.com/royal/userfiles/file/17544265341.pdfIn PDF document text
    • http://jnnycc.org/userfiles/file/62502823191.pdfIn PDF document text
    • http://nawooelcs.com/upload/userfiles/2021/06/files/210613020629.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/ea05205c6fbb4998ea1504dc016bfcea/zajunexarefujasi.pdfIn PDF document text
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160aaa8524023a---silajesopimi.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/3c1e7146e801aec3343b8e5f1c42d284/xutasujuzode.pdfIn PDF document text
    • http://centralgiving.com/media/userfiles/file/45273453002.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/eb500af13816dcfe00c4628f3ca85ceb/dirodebux.pdfIn PDF document text
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/508m31946k44ob9gnc50cukj8m/zurixivuwokinetefekadi.pdfIn PDF document text
    • http://gdbchurch.com/clients/43262/File/59585617346.pdfIn PDF document text
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/ipcrusud6ru1lhmjb8kb53nj31/wawij.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=coughing+up+gray+phlegmPDF 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_off0000f93b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF93B 16876 bytes
SHA-256: 3ab81ae01510cd2f8986c7b20628033f1935124555ba5a97fc688754bb0ef49f
font_01_sfnt_off0001250f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1250F 10680 bytes
SHA-256: 3d4ec76d78b052cfede2c2d749f04071ace13ce27337aa36a70a642ee507fe9e
font_02_sfnt_off00013d57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D57 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1