Malicious PDF — malware analysis report

Static analysis result for SHA-256 55d77249c1376d24…

MALICIOUS

PDF

84.0 KB Created: 2021-07-02 11:25:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 8b86c629b2c18facfa9ced61fc2be315 SHA-1: 8ba250c7ebbd6383ba56cd3ccf9d9460f82551c8 SHA-256: 55d77249c1376d246e648bacc7b90537cd8fb257bc2e3ee891f7551defe797af
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised WordPress sites and disposable domains, indicating a link farm designed to lure users to malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or distributing further malware. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM specifically identifies the pattern of using disposable hosting for link farms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://chcial.ru/uplcv?utm_term=nutrition+facts+chart PDF link annotation
    • https://papiratisk.cz/soubory/89074939183.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/2n6eriqodte1sue1c5618eior5/safeko.pdfIn PDF document text
    • https://grandplaza.bg/uploads/assets/file/9965191693.pdfIn PDF document text
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/a9sdu2a2ent0u6thoeqnetocuo/64530239074.pdfIn PDF document text
    • http://nusratali.com/userfiles/files/1975610904.pdfIn PDF document text
    • http://armanetti.com/images/41739985202.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/widililedave.pdfIn PDF document text
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/i2p75h3tsd8pnk9lpar4j7q61a/29369871275.pdfIn PDF document text
    • http://aihyang.com/userfiles/file/fotojuzelitexir.pdfIn PDF document text
    • http://kfnmdg.com/upfolder/e/files/20210601091110.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160717497e1cf4---juvoki.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/16086b7b4cab2a---12544980003.pdfIn PDF document text
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/ttsc70e34ifkr4rc8j042dsfue/87523147435.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160dca94f6bdf2---52683541906.pdfIn PDF document text
    • http://bestbelly.org/content/files/files/2718490122.pdfIn PDF document text
    • https://www.alapan.org/fckimages/file/49115900713.pdfIn PDF document text
    • https://www.heracles-hotel.eu/wp-content/plugins/super-forms/uploads/php/files/791mgucdj7rtnffsj9esjh9ju8/69463970515.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609bbac938b81---gurubexoj.pdfIn PDF document text
    • https://dmvassociates.com/wp-content/plugins/super-forms/uploads/php/files/aa66c14c664e8316e39bd3d54c3bf579/31871138388.pdfIn PDF document text
    • https://hotelristorantenovecento.it/wp-content/plugins/super-forms/uploads/php/files/a296c62e4ccac0cde99ff5fe33bb62be/33179834182.pdfIn PDF document text
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/f8d4220404583037da479a9697b443a9/kotewuj.pdfIn PDF document text
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/65d0493152b27437f5546596e2e0f1cb/35879301334.pdfIn PDF document text
    • http://anandtouristcorporation.com/uploads/vulerediludepened.pdfIn PDF document text
    • 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_off0000e4f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4F2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fd09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD09 10332 bytes
SHA-256: b974b506fe71e2cb3a3d286534b93e826ce83fdab825017052c298ffba956f32
font_02_sfnt_off0001144e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1144E 17292 bytes
SHA-256: 670db30c7e3c1f9aaafa7662c626e3833a2fcd81ce04aa1e3ffed3ac801cb52d