Malicious PDF — malware analysis report

Static analysis result for SHA-256 c090a0f1e406ca3f…

MALICIOUS

PDF

82.1 KB Created: 2021-09-07 14:16:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: df294f56a9432377717d169c4eb3ed82 SHA-1: ca8c04fdc84035273e07f29ee84f7a950a20132a SHA-256: c090a0f1e406ca3f160a9f4f9b447cd23c767eab81eda23524a7a15dd97fa8be
96 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to other PDF files hosted on compromised websites. This behavior is indicative of a link farm, often used for SEO manipulation or to distribute further malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/16094ca10222b7---lazaj.pdf In PDF document text
    • https://fa-vietnam.com/webroot/img/files/90885977395.pdfIn PDF document text
    • http://lesbambousbleus.fr/ckeditor/upload/files/jivupefuz.pdfIn PDF document text
    • http://kartinatv.org/uploads/files/83552411360.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/bubutem.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/307f67cf2279b46338a863cf47fe3a02/womobizubuje.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e36fc86f9ca---kukijajajufuvareliba.pdfIn PDF document text
    • http://coumert.com/images/file/vikasudigira.pdfIn PDF document text
    • https://pasifikendustriyel.com/userfiles/file/87716682447.pdfIn PDF document text
    • http://arenda-v-novosibirske.ru/ckfinder/userfiles/files/nixirenezazagisutuzoke.pdfIn PDF document text
    • http://woori-tour.kr/FileData/ckfinder/files/20210731_46F55922A912BBDC.pdfIn PDF document text
    • https://lanjutpt1.com/contents//files/giduti.pdfIn PDF document text
    • http://www.empresasdelimpeza.info/wp-content/plugins/formcraft/file-upload/server/content/files/1608eb38aed092---73146033139.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/16078a36fed529---roxutovefawakedupibone.pdfIn PDF document text
    • http://surtek.biz/image/files/20150120_001638.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607598e16b695---43223401588.pdfIn PDF document text
    • http://savages.lu/imagesRTE/files/tosojopudexarimamutawofal.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b4b9b16711---tejesavajanusas.pdfIn PDF document text
    • https://windsbs.biz/files/file/solarar.pdfIn PDF document text
    • https://info-jimukyoku.jp/lot/upload/files/xivozaxalaxamef.pdfIn PDF document text
    • http://growlink.biz/userfiles/file/69745541064.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1ace733190---gafemasuzag.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=depression+anxiety+and+stress+scale+pdfPDF 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_off0000db73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB73 10832 bytes
SHA-256: 4418772b8ae656ea079ae2167d17dc950c0b6b164a630f9bd40bdf7de1403b65
font_01_sfnt_off0000f495.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF495 17644 bytes
SHA-256: b73ee5599bbb0694e899efaa1abf6674d2b50c2011eac62fa17b238ef976bed5
font_02_sfnt_off00012279.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12279 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1