Malicious PDF — malware analysis report

Static analysis result for SHA-256 87162b00cd85f084…

MALICIOUS

PDF

135.5 KB Created: 2021-06-25 20:48:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: a1b9f0ecbc49d1ed31ddc1a8db4b4c28 SHA-1: 3fa31fd709a20478fe7a28446769f265888f4bc0 SHA-256: 87162b00cd85f084487278c16b979accda11629d3ef92174155c34f418564bcd
156 Risk Score

Malware Insights

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

The PDF was identified as malicious by a machine learning classifier and ClamAV, with heuristics indicating it functions as a link farm. Multiple URLs point to compromised WordPress sites and disposable hosting, suggesting an attempt to redirect users to malicious content. The document body is heavily obfuscated and unreadable, providing no direct clues to its specific purpose beyond the link farm behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9914

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://www.ogblfrontaliers.fr/wp-content/plugins/super-forms/uploads/php/files/eit0v4879r6gj0kkctjbb323so/17254454650.pdf In PDF document text
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/22suqp7cfkhle5fur75ka3b6v3/79149154256.pdfIn PDF document text
    • http://savaksangida.com/resimler/files/7390343007.pdfIn PDF document text
    • http://midiabyz.com/wp-content/plugins/super-forms/uploads/php/files/8207b7bea297add86ff478eddb4f73b3/76087670263.pdfIn PDF document text
    • http://gorisum.net/fckeditor/upload_file/file/dogedesajoke.pdfIn PDF document text
    • https://unicornproduction.gr/wp-content/plugins/super-forms/uploads/php/files/fefdcd5e611d2840a628c712c67520be/8097725948.pdfIn PDF document text
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/jnv02vnqpvnnmeepmii3um1vvf/xesebedaw.pdfIn PDF document text
    • http://anhuishangbiao.com/upload_fck/file/2021-5-21/20210521072126155297.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/31aa2ldq0674646go15kha3mft/61199864530.pdfIn PDF document text
    • http://rockycheng.com/ckfinder/userfiles/files/65304146514.pdfIn PDF document text
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607373827e432---zulajevijo.pdfIn PDF document text
    • https://k2salight.com/wp-content/plugins/super-forms/uploads/php/files/4774b83a0c6ea72932b3e89cae15d218/16147341980.pdfIn PDF document text
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/b173581ddd540a0603f7b32059b3a006/xokixigavewuvixuf.pdfIn PDF document text
    • https://southernlightingsource.com/wp-content/plugins/super-forms/uploads/php/files/9401000aa9779f7e0072d3c3cd26bbcf/54037646876.pdfIn PDF document text
    • https://aplusadvance.com/naver_editor/data/file/28927972904.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9429a17b8f---vewelota.pdfIn PDF document text
    • https://outsourcedbackoffice.co.uk/wp-content/plugins/super-forms/uploads/php/files/244232b93b0c357dbd82031fc632d0d5/ramokirivoberowerekevo.pdfIn PDF document text
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/4f9f9abb7e5922d5ae189c1dcf6aa85a/lorawepibiwe.pdfIn PDF document text
    • http://svaz-podnikani.cz/files/file/mudowumumefowewajazanadov.pdfIn PDF document text
    • https://dm288.com/slicice/file/puvataxineganipobawejaz.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/ef6bddf9e6759c5e526f31630212d4c2/44361962028.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/c1d986f620f5380cdb1a03e84dcfce74/44374095669.pdfIn PDF document text
    • https://theatresaucinema.fr/uploads/file/rororixa.pdfIn PDF document text
    • http://aimecostruzioni.it/userfiles/files/fawukolutiwuguref.pdfIn PDF document text
    • http://www.dismaplant.com/ckfinder/userfiles/files/pusijaj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=there+will+come+soft+rains+by+ray+bradbury+summaryPDF 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_off0001ad7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1AD7E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001c590.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C590 17684 bytes
SHA-256: 31110594b39365fb70e397a8e1787dbf99e41ed9b7eeca9bcacd54b40c73c513
font_02_sfnt_off0001f414.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1F414 11144 bytes
SHA-256: 23a1d96f2129d481fbc83190986ad1c19a3703e7e472fc9d579d15277b923687