Malicious PDF — malware analysis report

Static analysis result for SHA-256 f335175420287b26…

MALICIOUS

PDF

85.0 KB Created: 2021-09-08 12:48:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: de8376c083e69787989533ae3ff4eabb SHA-1: 78645259d8aad502803a89cd7e13200f23ae64c6 SHA-256: f335175420287b26ac59498a85ce4ff6e9b6a503a5e1c6f3a83ce39c20281088
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and multiple heuristics indicate it is a link farm pointing to compromised websites, likely for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. The embedded JavaScript is likely used to redirect the user to one of the listed malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/d910do4sd4n47vko19ecledir1/83761782502.pdf In PDF document text
    • https://fcksa.com/ckfinder/userfiles/files/wosokafuzimopubenagaso.pdfIn PDF document text
    • http://chulatutoracademy.com/chulatutor/ckfinder/userfiles/files/93448194890.pdfIn PDF document text
    • http://gnox.vn/upload/files/69562230405.pdfIn PDF document text
    • http://saga.diamonds/uploads/ckfinder/files/24623197656.pdfIn PDF document text
    • https://es21sys.com/userfiles/file/70206592336.pdfIn PDF document text
    • https://riondene.ch/img/uploads/file/37152459045.pdfIn PDF document text
    • http://tuzvedo.hu/elemek/file/19581012259.pdfIn PDF document text
    • http://tanabuauto.com/js/upload/files/suvubokoxofibateko.pdfIn PDF document text
    • http://thelonerangerfanclub.com/ckfinder/userfiles/files/barak.pdfIn PDF document text
    • http://jjburgerut.com/uploads/files/62801205397.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161367952c3ea1---66332470604.pdfIn PDF document text
    • http://saigonford3s.com/uploads/2021-09-05/images/files/66163214134.pdfIn PDF document text
    • http://www.mezmat.ru/ckfinder/userfiles/files/42837291582.pdfIn PDF document text
    • https://apaman.ti-am.jp/js/ckfinder/userfiles/files/zefajitiwepasagetefepe.pdfIn PDF document text
    • http://pibar.tw/uploads/files/202109030911386381.pdfIn PDF document text
    • http://suurelepa.ee/data/file/25570577799.pdfIn PDF document text
    • https://chachachat.info/js/ckfinder/userfiles/files/sazusit.pdfIn PDF document text
    • http://warehousetraining.ie/images/93158616274.pdfIn PDF document text
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/254bd47b6306cb89888557bfd8368aea/zogusulakusev.pdfIn PDF document text
    • http://qiangka.com/ckfinder/userfiles/files/soketejamorod.pdfIn PDF document text
    • http://happinessgown.com/upload/users/files/93118364402.pdfIn PDF document text
    • http://matchonusa.com/uploads/files/93256400771.pdfIn PDF document text
    • http://steelfurniturecn.com/d/files/58192578925.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=california+lease+agreement+template+pdfPDF 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_off0000e5ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5EE 10872 bytes
SHA-256: 0b04980a6b8a5304a66a1e66d61192cb458c8b733fbaa79a6f0ef2f46e0ae5fe
font_01_sfnt_off0000fed1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFED1 18232 bytes
SHA-256: 859eb8bfc8c5cc99c760c5dad7d3de9378ca837a0aaa08420782985a0dd58354
font_02_sfnt_off00012e40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E40 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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