Malicious PDF — malware analysis report

Static analysis result for SHA-256 18bec4077d759c9f…

MALICIOUS

PDF

72.6 KB Created: 2021-07-14 05:19:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0b9e95f9b5284fa660bcdfd40e2a1138 SHA-1: 591c256d39b7c77697dc5e0e52931d3c2ced2bd8 SHA-256: 18bec4077d759c9f042570fb2cf8f3ca153a5de0ae48c1d9536402bb7e562cd0
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of embedded URLs, many of which point to compromised WordPress sites and disposable domains. The ML classifier strongly indicated maliciousness, and the heuristic firings suggest this PDF is a link farm designed to redirect users. The primary purpose appears to be SEO manipulation or distributing further malicious content through these numerous links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://oniceh.ru/uplcv?utm_term=multiprogramming+with+fixed+number+of+tasks
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606d658d48922---gumekutenaxafesadenidide.pdf
    • https://ecomassage.pt/wp-content/plugins/super-forms/uploads/php/files/pvd4bgjoa2l4tm8m32m7f67983/tewupadigipijiziba.pdf
    • https://datajournonepal.org/files/12140149569.pdf
    • https://xn--22ck6bdp5cach0mc23a.com/ckfinder/userfiles/files/70810760924.pdf
    • http://findmealocalpainter.com/insurazon/admin/userfiles/file/ruwafiwilileduwapaje.pdf
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/98abdf2219139a37d02b3f346f96fbd0/mepij.pdf
    • http://xn--k1akb4c.xn--p1ai/userfiles/file/weduletimewoguli.pdf
    • https://pousadamarazul.tur.br/wp-content/plugins/formcraft/file-upload/server/content/files/160948a9d2c619---22358945538.pdf
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/57062a639cb2e7aba848e405f1782167/zifedutofilalapixepo.pdf
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e686327669---wesemipenulasinazo.pdf
    • http://varanini.pl/userfiles/file/mukomavaseruvituwosugeri.pdf
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/263d3579f5affffa1f46e2d9ea0398e4/52533037947.pdf
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/g78d61u3v9naer5bv3t0d1ui90/kifope.pdf
    • http://www.molinoag.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c15434e3e8d---xotojafex.pdf
    • http://zavalinka.by/var/upload/file/51690391199.pdf
    • http://clair-environnement.eu/catalogue_dynamique/file/40439701346.pdf
    • http://hytechplus.com/userfiles/file/wagifovebokowuwadu.pdf
    • https://atx-stroy.ru/wp-content/plugins/super-forms/uploads/php/files/66af85d35760dfb1b23e446e2411f2cd/78570012685.pdf
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1608ad972b8e61---daposodisuzevoj.pdf
    • http://teplospectr.ru/images/files/8734514839.pdf
    • http://dyglas.com/userData/board/file/zagadusifolonese.pdf
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16086ec40c9853---korulefogafikoruve.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b563.bin
008f1ebd181d0aad521c5059503b9004bc82d88b6077097b5dc265103649a7d2
pdf-font-stream PDF embedded font (sfnt) at offset 0xB563 11456 bytes
font_01_sfnt_off0000cfea.bin
4b472d46ef4a5dd46ef07fc25311a4eba4b6a89ca9b49b04c36e8ecebb17c8da
pdf-font-stream PDF embedded font (sfnt) at offset 0xCFEA 17104 bytes
font_02_sfnt_off0000fd00.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD00 16792 bytes