Malicious PDF — malware analysis report

Static analysis result for SHA-256 8fbb4e1543593b5b…

MALICIOUS

PDF

80.9 KB Created: 2021-09-10 19:18:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 8edf7b807d3e24878145fa0db43f6fde SHA-1: f3370185ef5a2e210b2147882a403c9eb19caaa4 SHA-256: 8fbb4e1543593b5b728a8fe1762c1b528a851270b05a0d25e16ea5ed29978567
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm directing to multiple PDF files, with several hosted on compromised CMS upload directories. The ML classifier strongly indicated maliciousness. The document body is heavily obfuscated and unreadable, suggesting an attempt to hide its true purpose, which is likely to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://rizecanreklam.com/images/file/xubesiduforofuzigori.pdf In PDF document text
    • http://nghiencuuykhoa.com/uploads/userfiles/file/fivobamodakeriporukero.pdfIn PDF document text
    • https://airin.lv/images/userfiles/file/biwokefijedu.pdfIn PDF document text
    • http://clear-es.net/yamituki-n/uploads/files/42358016122.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/161304b06c9377---xidunefetokironari.pdfIn PDF document text
    • https://yarpaket.ru/userfiles/file/lobozasijub.pdfIn PDF document text
    • https://mackbeks.com/files/file/nosaboguzu.pdfIn PDF document text
    • https://beytarimcilik.com/admin/editor_resim/file/ruludamisatopasuzubudo.pdfIn PDF document text
    • http://tubemakingmachine.com/uploadfile/files/24621473986.pdfIn PDF document text
    • http://fixmyhelicopter.com/project-new/christianbook/upload_images/file/ledademazelosebepeze.pdfIn PDF document text
    • http://avvocato-callegaro.it/public/file/97391782283.pdfIn PDF document text
    • http://www.coverseg.com/uploads/ckfinder/files/zivuvilumovugojuxemuxad.pdfIn PDF document text
    • http://autoandtruckrepair.net/nbloom/fckuploads/file/51299114422.pdfIn PDF document text
    • https://bandotrading.com/uploads/file/vadajewudepifesozux.pdfIn PDF document text
    • http://napiarsaigh.com/images/jewezilunilow.pdfIn PDF document text
    • https://hgb.se/filer/file/48246736036.pdfIn PDF document text
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613120c035ab7---34440653459.pdfIn PDF document text
    • http://bentleyplemtech.ru/userfiles/file/8473934212.pdfIn PDF document text
    • http://thementalhealthadvocates.org/files/userfiles/file/nawuvukunaju.pdfIn PDF document text
    • https://dispomydeal.com/wp-content/plugins/super-forms/uploads/php/files/427494e42ad14b84f82ae5226b52a161/79367177634.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613aea11f0024---fodogefik.pdfIn PDF document text
    • http://www.mueblesgamez.com/ckfinder/userfiles/files/43079130621.pdfIn PDF document text
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161371abef20f2---lilunitekekutukegexok.pdfIn PDF document text
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133a655ec137---dopevovuwaporixotejos.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=how+to+know+airpods+battery+on+androidPDF 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_off0000d719.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD719 10760 bytes
SHA-256: 55ecd3f54842f12e720ad30ddbb7ad174865e17309325678375c57142cf14c3c
font_01_sfnt_off0000efcd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFCD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000107df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107DF 17616 bytes
SHA-256: 5175ae1fde7a9357e1f832b576a310fcd2176a0ef082e04cf13cbf740027d10f