Malicious PDF — malware analysis report

Static analysis result for SHA-256 c23a00ecb6602c21…

MALICIOUS

PDF

84.4 KB Created: 2021-09-22 11:08:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 6f41c34e7aad1244fdb137467b4e2adc SHA-1: c52b0b11a162c1ee4c95cea889b72fd18d606711 SHA-256: c23a00ecb6602c21c46777a36c2d4e2776863ddd735c70316093e9b6bbc245ac
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as containing a link farm pointing to potentially compromised WordPress uploads and disposable hosting. The ML classifier and ClamAV also identified it as malicious, specifically as a phishing trojan. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://wastran.ru/uplcv?utm_term=wonder+woman+1984+movie+2020+online PDF link annotation
    • https://www.tahitotfalu.hu/ckfinder/userfiles/files/jezalafim.pdfIn PDF document text
    • http://reklamaopole.pl/userfiles/file/48413984729.pdfIn PDF document text
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/n3clhq9gc7qcsh38om45e1ets7/29116128872.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/16133d2d97db45---vuwubo.pdfIn PDF document text
    • http://aliceinformaticasrl.com/user/pages/13190542533.pdfIn PDF document text
    • https://investkwik.com/userfiles/file/gobetefovaxusasatekoril.pdfIn PDF document text
    • http://aotwcasino.com/ckfinder/userfiles/files/rotadoxozetazivenupusakov.pdfIn PDF document text
    • https://elemental-ia.com/userfiles/file/5814857249.pdfIn PDF document text
    • http://growlink.biz/userfiles/file/89863940463.pdfIn PDF document text
    • http://c-six.it/userfiles/files/zimomozuw.pdfIn PDF document text
    • http://sunnysolutions.it/uploads/assets/file/9253704667.pdfIn PDF document text
    • http://traditionsradio.com/wp-content/plugins/super-forms/uploads/php/files/3211e81fd7e82f1323437f4c79e95605/fawikivareboranumuvul.pdfIn PDF document text
    • http://xn----gtbercbfedtm3b.xn--p1ai/admin/ckfinder/userfiles/files/wojoxalexatonutefe.pdfIn PDF document text
    • http://chiaranannini.com/userfiles/files/rasomajajiteturexonuretil.pdfIn PDF document text
    • http://archiw.gbpopatowiec.pl/img/upload/files/fubufiwumimogitip.pdfIn PDF document text
    • https://wittnebel.dk/file/fufaxuvixil.pdfIn PDF document text
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/uhhkqqn29no44g3jmct1c6oi9i/35684343699.pdfIn PDF document text
    • https://taiwancy.com/app/webroot/userfiles/files/videgebek.pdfIn PDF document text
    • https://klaipeda.cvzona.lt/resources/img/files/tovef.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bf5d71f700---83016309528.pdfIn PDF document text
    • http://scea.edu.mn/ckfinder/userfiles/files/1320394552.pdfIn PDF document text
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613828cc38357---mibipul.pdfIn PDF document text
    • http://lexen.ca/userfiles/files/18032655598.pdfIn PDF document text
    • https://marblo.com/app/webroot/img/files/711789970.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_off0000e34d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE34D 11036 bytes
SHA-256: 5e9eefe085078c57c9f89acc5352f1e52de566f9d0520496e1fad322413741e1
font_01_sfnt_off0000fd18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD18 18248 bytes
SHA-256: 4c35f3aa6be0bb07b286906fc6ac85b6dd156163163bb67c63ae72e24784972f
font_02_sfnt_off00012c29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C29 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1