Malicious PDF — malware analysis report

Static analysis result for SHA-256 52a88d30417dac8a…

MALICIOUS

PDF

70.2 KB Created: 2021-09-28 22:47:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: cc5fc740c71d6366cabf011ad1755210 SHA-1: 483e715796426a913acc46d68cba7fe62309277a SHA-256: 52a88d30417dac8a4cf6dc9291d704c48c058cde955226b44cd843c4debf09ef
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm for SEO poisoning or malicious redirection. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the structure and URL patterns suggest an attempt to lure users to external, potentially malicious, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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://arc-en-cielproduce.com/ckfinder/userfiles/files/pilodosimox.pdf In PDF document text
    • http://dulichgiahy.com/upload/file/76112129341.pdfIn PDF document text
    • http://cobweb.janci.net/upload/files/48471296491.pdfIn PDF document text
    • http://ch-yang.com/upload/files/najife.pdfIn PDF document text
    • http://bortran.com/upload/image/file/20210910013311.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614fde5de40da---86603630827.pdfIn PDF document text
    • http://maychamsocda.vn/images/userfiles/file/74728060310.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/161416430140a8---66351155702.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16136f98e51659---3472117792.pdfIn PDF document text
    • http://net-work.cz/data/file/16627700460.pdfIn PDF document text
    • https://hongming-eco.com/userfiles/file/71267909805.pdfIn PDF document text
    • http://terezmisszio.eu/files/file/6569743955.pdfIn PDF document text
    • http://weilandensemble.nl/ckfinder/userfiles/files/mibesawegigi.pdfIn PDF document text
    • http://vattucongtrinh.com/userfiles/file/fuxexodujetimikekozan.pdfIn PDF document text
    • https://olterus.org/contents/files/26629332072.pdfIn PDF document text
    • http://exito-opakowania.pl/userfiles/file/54878615253.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/f2vbuerbgpdo06a3eanibucqie/10674513425.pdfIn PDF document text
    • http://faradtvandor.hu/picture/userfiles/file/9589957526.pdfIn PDF document text
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/1ab17a800f25b5142b31c636e078f776/bowarufun.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/d2ddkjs1amhrp7ftnalishads1/38046203312.pdfIn PDF document text
    • https://aqua2go.pl/galeria/file/tivelebojiweludurab.pdfIn PDF document text
    • https://mami-m.com/Uploads/userfiles/files/31155499262.pdfIn PDF document text
    • http://mensagemcrista.com.br/ckfinder/userfiles/files/46917324145.pdfIn PDF document text
    • http://boki.hu/editor_up/37461221891.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/0908492ec09e1d3f6c82a99f9b406e47/musaxavuwikeminoxukajijo.pdfIn PDF document text
    • http://perchegouet.com/ckfinder/userfiles/files/petum.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=how+to+stop+amber+alerts+on+android+phonePDF 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_off0000b576.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB576 14632 bytes
SHA-256: 5f4aa7cbac87327909c419b761fe5e9bf8f812e0ca7fd91b60ed7a8c1d7ace23
font_01_sfnt_off0000d9fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9FE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f215.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF215 10876 bytes
SHA-256: 52b8642b9c2de8bdb9f25203ad0a215d04cdf6431e5115417874108e9fb51b2b