Malicious PDF — malware analysis report

Static analysis result for SHA-256 871ba249d71b79c8…

MALICIOUS

PDF

87.7 KB Created: 2021-06-29 02:34:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e4cd4f2774ad57d6adb812850ac79314 SHA-1: c77db77c154fde30a81531c70550c9f872e4c248 SHA-256: 871ba249d71b79c8e8d9dee33f91df7ad384d0e795de50914af371a4cfcce25c
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress upload storage and disposable hosting, suggesting it's designed to redirect users to malicious sites. The embedded URLs, such as http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/1a36cea980cd5fd2f2574d2e606c28dc/tuwuviwubarurebiduso.pdf, are key indicators of this redirection behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cfbff06e2a9---90729215632.pdf
    • http://www.asslar.de/downloads/wipudararowapajom.pdf
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7d5d5d083f---dezanitemibeder.pdf
    • https://www.zulilighting.com/wp-content/plugins/super-forms/uploads/php/files/dec5d1ba7f0aa77ba8b6ab5a3c9d0080/61194677365.pdf
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c920768fe1c---jivebujokikekax.pdf
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/1a36cea980cd5fd2f2574d2e606c28dc/tuwuviwubarurebiduso.pdf
    • http://vienkiemis.lt/app/webroot/uploads/userfiles/files/gujoxezagorivinasosisus.pdf
    • https://hafa-verein.de/wp-content/plugins/super-forms/uploads/php/files/9c91b11782b8ddfe86513ab4c0480a21/kizimo.pdf
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/ce5e050c59e74760e003bf24cf5dd239/45194427855.pdf
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2ecd490d49.pdf
    • https://myhoorayhealth.com/wp-content/plugins/super-forms/uploads/php/files/uhvq76h0af2i5t6bsfuef41ns2/32865010017.pdf
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/1a6b6fa942e16ca6f86f1cfa36a9c14a/78130731414.pdf
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/mhud3ci61pdtskude4ea60gci5/89977428725.pdf
    • http://aftckwt.com/uploads/file/figawalemewobazebixusuxe.pdf
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/ttcsugr5ahj37qgs0sf19pta0m/zevusuk.pdf
    • https://aannemingsbedrijfbarthulsbosch.nl/userfiles/file/26265075334.pdf
    • http://noxsun.com/jingkelun/userfiles/files/20210628210734.pdf
    • https://www.rekalibracija.com/wp-content/plugins/super-forms/uploads/php/files/0fb204ad52bf6f145703490c11d9fbc3/14438207644.pdf
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607b02a273b98---zevizevugasupemo.pdf
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/e55el4ppp7cdh01o1s3h4pkoc2/76899939711.pdf
    • https://www.alpha-dynamics.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1606fdc8cde0b6---tusad.pdf
    • https://alrashed-alsaleh.com/userfiles/files/1965843508.pdf
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16086d49d8cf55---mowefazewadojapu.pdf
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/9042b73ba57f2138992d729b7bcd87f1/noluxivuwe.pdf
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607f7abddc4a8---50070492261.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=gardenscapes+how+to+make+dynamite
    • 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_off0000f223.bin
92f4f7a200b69bea8927a439d8692ccdc94fd0db5c1a70e3bb774d98fe83e5a1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF223 17720 bytes
font_01_sfnt_off00011f5c.bin
71bac6a1f4806a8b0f9947d80f859d7b0876ce65c5679565a24c3c37fab037c7
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F5C 11064 bytes
font_02_sfnt_off0001390c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1390C 16792 bytes