Malicious PDF — malware analysis report

Static analysis result for SHA-256 57c23216ccdc5708…

MALICIOUS

PDF

78.4 KB Created: 2021-09-07 05:44:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 3034932176d753ed30bada4c2fe0ce49 SHA-1: 8e009e87a4c0588ae6faed1b4b3ecc60dcbd7bad SHA-256: 57c23216ccdc5708dd787805c88cd3692d0565025bbdcbeb8bbda2a69dfd1b64
96 Risk Score

Malware Insights

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

This PDF file was identified as malicious by an ML classifier and exhibits characteristics of a link farm. It contains numerous URLs pointing to PDF files hosted on compromised CMS uploads, suggesting an attempt to manipulate search engine results or distribute further malicious content. The presence of multiple links on disposable hosting and compromised WordPress sites indicates a coordinated effort to spread these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://laptopcuhaiphong.vn/upload/files/sedegepamukuvuxumexuvobux.pdf In PDF document text
    • http://kids-ex.com/41346928582.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/160a1c82a90fcd---nebubulodur.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/1344f268e2135ec532489ff549e3c190/vutitidufonuja.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/16100869c3c71a---33472963576.pdfIn PDF document text
    • https://www.htlexpress.com/ckfinder/userfiles/files/beleni.pdfIn PDF document text
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1606ceac507cb9---noxakikebukinogux.pdfIn PDF document text
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/6scdfk998l8ntpj4niapa4od87/25345468743.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e932edf562---bulipuvesezumapike.pdfIn PDF document text
    • http://transbur.ru/admin/ckfinder/userfiles/files/xetinulefage.pdfIn PDF document text
    • http://szao-spb.ru/images/news/file/88320464073.pdfIn PDF document text
    • https://n-v-v.dk/userfiles/file/47257457657.pdfIn PDF document text
    • https://bikeid.net/ckfinder/userfiles/files/fotafodeduwomi.pdfIn PDF document text
    • https://ooobelkom.ru/ckfinder/userfiles/files/falipoxawituxexijusirunu.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ad7d91c80f---legivekipexi.pdfIn PDF document text
    • https://inverpalmas.site/aym_image/files/rulujameniweroses.pdfIn PDF document text
    • https://ikitellirezistans.com/upload/files/ritasavidinoganenoziva.pdfIn PDF document text
    • http://rrmkaryacollege.org/rrmkarya/userfiles/file/mamumurolitebonub.pdfIn PDF document text
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a7ca191e725---34491850645.pdfIn PDF document text
    • http://www.kotolantopeni.cz/files/gotekosabusakadunuvi.pdfIn PDF document text
    • http://alrabbancapital.com/file/files/lopojezuzelimobotaxekelif.pdfIn PDF document text
    • http://toyotarenta.net/FileData/ckfinder/files/20210725_AA213D41A35FF883.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132838a66b8b---31614019636.pdfIn PDF document text
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/89786510c0c1320a8483126728b30aff/4169998933.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=interpolacja+liniowa+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_off0000cb0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB0D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e324.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE324 10612 bytes
SHA-256: cd1b23704527d5a63c3cae7a42c0811e9d873a97baeba122085a0b8c2dfb6317
font_02_sfnt_off0000fb7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB7D 18368 bytes
SHA-256: 27eb163a6bcebb1482dd9bc3c34f3a59b8b0ad13cf82ee551ebca78af4583b81

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