Malicious PDF — malware analysis report

Static analysis result for SHA-256 8249034927dd23f2…

MALICIOUS

PDF

96.0 KB Created: 2021-09-03 08:33:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 6e705640f1ec384cd8737cdf0ea92948 SHA-1: 5b10a9bd3c7a275fac4f656a81e3695d2b0ac952 SHA-256: 8249034927dd23f25f98c9ae5cfbfe7d9772bf910dcfc8c0a924347a0f4db02f
96 Risk Score

Malware Insights

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

The PDF document contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable domains, indicating a link farm designed for SEO manipulation or to distribute further malicious content. The ML classifier also flagged this PDF as malicious with high confidence. No scripts were extracted from this sample, limiting the analysis of direct execution capabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9820

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://krisoc.ru/uplcv?utm_term=how+to+learn+spanish+pdf+free+download PDF link annotation
    • https://vinocastillo.hu/editor_up/bumizanegeritefitodirep.pdfIn PDF document text
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/a5ec6af0290cdc142d146c1d5fc6a954/mipigepigopolireniw.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adc64591bea---wakuge.pdfIn PDF document text
    • https://beruanglucu.com/contents//files/77510805304.pdfIn PDF document text
    • http://novastal.pl/userfiles/file/93732939460.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/jemcridj10vn6a1eg0f7ocr57v/46362055879.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607807178734b---vosodibapegibisalosoxerol.pdfIn PDF document text
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/66d68c7aaaa424f1d68d1ad668187817/63972733957.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606cfbb1b4ae3---27088165256.pdfIn PDF document text
    • http://plenaadoracao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a51ecc5e681---laniwapenatowuvapawomoki.pdfIn PDF document text
    • http://emailreceptionist.net/userfiles/file/nomeruwaxezijamopulul.pdfIn PDF document text
    • https://lea-inc.com/wp-content/plugins/super-forms/uploads/php/files/fd66a1114b527b6f5eaa069e4d503e6d/juxapasatad.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608d37d868630---31222142864.pdfIn PDF document text
    • http://vako.vn/app/webroot/uploads/files/pafusamum.pdfIn PDF document text
    • https://andrejc.si/files/file/28965223797.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fd9ba35ef9e---54104370214.pdfIn PDF document text
    • https://gazelletr.com/userfiles/files/289289891.pdfIn PDF document text
    • https://www.digitalsofts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fe230ebfaf4---50979240654.pdfIn PDF document text
    • https://sitycare.com/FCK-UserFiles/files/88950068819.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/b872c107b1fbc797fa221901e88068f4/zupaz.pdfIn PDF document text
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ccba844ac3---64493325475.pdfIn PDF document text
    • http://www.apsetedavisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160814148ab8ad---7251789202.pdfIn PDF document text
    • http://ryyw.com/upload/files/2021/08/202108181015024311.pdfIn PDF document text
    • https://www.plsok.com/wp-content/plugins/super-forms/uploads/php/files/97a730f3c5fa3212267bbead6c79ad83/fujinuwi.pdfIn PDF document text
    • https://premiumvipbusiness.com/wp-content/plugins/super-forms/uploads/php/files/cff8cb46b371e00ccc53014c2e184e6c/zofazodedekezixosigorek.pdfIn PDF document text
    • http://sequirk.ie/userfiles/file/rugagimirilodizubeg.pdfIn PDF document text
    • 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_off00011116.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11116 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001292d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1292D 10672 bytes
SHA-256: fe6c0dfa0bed69622ced44371fbb8e95d5fa5001905b4a9577d323128ae88034
font_02_sfnt_off0001418b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1418B 18800 bytes
SHA-256: c5901692549aa711c58e037335674cc03364bc7025e4e11279ca1e73cb8a93aa