Malicious PDF — malware analysis report

Static analysis result for SHA-256 5653b52fac16c361…

MALICIOUS

PDF

88.2 KB Created: 2021-08-19 21:05:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: ca060a8ed18e26c2af007cd8eae2631a SHA-1: 2ee441dc5e4e02dd0d2fabaab2d4355ec8ee0cc6 SHA-256: 5653b52fac16c36185dc3b4d7c81738fe37c6568c662ca28efcc327537d8c6db
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous compromised WordPress sites, which in turn host other PDF files. This structure suggests a campaign to distribute malicious content or phish users by leveraging multiple compromised domains. The ML classifier strongly indicated maliciousness, supporting this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9919

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://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099eab4ad079---bufefuworofezabulutikuza.pdf In PDF document text
    • https://wecafephuket.com/wp-content/plugins/super-forms/uploads/php/files/j1f3mau06jooriuu2omgruegu2/nasonojevimosidu.pdfIn PDF document text
    • https://canadiancontractorservices.com/wp-content/plugins/super-forms/uploads/php/files/hqc2qnnotprr36dvmo52q7pvu2/guropogufas.pdfIn PDF document text
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/hnei95nqrh325kjdao5h7t0gus/41786836968.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160da9ba068245---danebebilude.pdfIn PDF document text
    • http://pincailight.com/zk/UploadFile/file/2021081822351373499.pdfIn PDF document text
    • http://pilot-market.ru/new/files/file/bidawike.pdfIn PDF document text
    • http://www.armstrongre.com/files/files/fusijo.pdfIn PDF document text
    • http://speakingaboutnetworking.com/ckfinder/userfiles/files/bomuxu.pdfIn PDF document text
    • https://firsatpin.com/calisma2/files/uploads/88996685239.pdfIn PDF document text
    • http://asiavent.com/UserFiles/file///kovudubamixiraxujumobumi.pdfIn PDF document text
    • http://shinies.ru/img/lib/file/11327902013.pdfIn PDF document text
    • http://stavclearing.ru/upload/files/3040783574.pdfIn PDF document text
    • http://erdbau-rauch.at/guwodemogawamal.pdfIn PDF document text
    • https://wisserarm.nl/app/webroot/files/userfiles/files/pijituzitevajaporaviwate.pdfIn PDF document text
    • http://biplano.eu/userfiles/files/78581770757.pdfIn PDF document text
    • https://thebottombillion.org/business_school/uploads/file/66463031560.pdfIn PDF document text
    • http://pm-ural.com/uploads/files/56420632988.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/160d93aa585559---62233340825.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fd20e3db74---29546166377.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/0e4f8fb89934e4f6b2be5954aa9e475e/60576615654.pdfIn PDF document text
    • https://egokituz.org/files/galeria/files/10483170716.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/pigawikajepixebututiz.pdfIn PDF document text
    • https://rcvizovice.cz/ckfinder/userfiles/files/98711768646.pdfIn PDF document text
    • http://ibookingkr.com/FileData/ckfinder/files/20210804_4C9CF75CFAACFD53.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160a02eb187c94---dumabapel.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=what+blocks+make+villagers+jobsPDF 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_off0000f42f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF42F 16948 bytes
SHA-256: 0960ad642ebcce267385b660e877ba27cb106502c930325fd5f401ff4c5d0e4b
font_01_sfnt_off0001207e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1207E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013895.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13895 10992 bytes
SHA-256: 8de3b3cc8cd12ab644cf741ba16f20c72cdbb0b8775a0c02ab65a7cee8c184c3