Malicious PDF — malware analysis report

Static analysis result for SHA-256 da20c30f07b48555…

MALICIOUS

PDF

68.9 KB Created: 2021-09-24 20:33:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f2e9e664ed72dea5d22f89f35201a7eb SHA-1: 313474128a71dd3cea205b21ea79bbf6ff7775d1 SHA-256: da20c30f07b485556fd4a4d820c69044d0a9fa39f6052c611fc87b20cae8d0b6
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to PDF files hosted on compromised websites, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable, but the URL structure is sufficient for a high-confidence assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/1614b706ba2d4c---zirez.pdf In PDF document text
    • https://nieruchomoscikomercyjne.co/files/file/64463264715.pdfIn PDF document text
    • https://cr2tek.com/userfiles/Proj_Name/files/8046122881.pdfIn PDF document text
    • http://rpsbchamber.org/editorData/file/12722747945.pdfIn PDF document text
    • https://telenovella-bg.com/files/dimimebalumuxiwezituwaku.pdfIn PDF document text
    • http://fishtech.org/uploads/userfiles/file/file/14884861247.pdfIn PDF document text
    • https://moniimpex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143160d9823a---55699564416.pdfIn PDF document text
    • http://ssatripoli.org/userfiles/file/79558688815.pdfIn PDF document text
    • http://jmyhship.com/uploadfile/files/79064862311.pdfIn PDF document text
    • https://pima-alarms.rs/slicice/file/92103443218.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/jopojawikuvajodimujunas.pdfIn PDF document text
    • http://goodfortune.hk/UpLoadFile/file///47854957163.pdfIn PDF document text
    • http://joy05.com/_UploadFile/Images/file/19743133530.pdfIn PDF document text
    • http://www.kizkulesikizogrenciyurdu.com/public/ckfinderuploads/files/weneruweguwijezobunin.pdfIn PDF document text
    • http://accutindustry.com/Upload/files/20210916082739.pdfIn PDF document text
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/1e84908d0fd167ce4fd91f572a9a2ca8/91924576574.pdfIn PDF document text
    • http://diegogenna.it/userfiles/files/petitawowebafurutuditamex.pdfIn PDF document text
    • https://kvizek.hu/ckfinder/userfiles/files/49734083296.pdfIn PDF document text
    • https://nexusmediation.nl/files/14329029374.pdfIn PDF document text
    • http://maychebiengoduykhuong.com/media/ftp/file/32778383563.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/161410ee69219f---bowegewolo.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614772fabcbeb---mowijegiluxitopititeje.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=free+casino+slot+games+for+androidPDF 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_off0000ad25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAD25 15308 bytes
SHA-256: 99d9719538c6d7e6abd7d6a9e5346cbb0befa3d2e8e054a1a58a930b2aa80f32
font_01_sfnt_off0000d3d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3D5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ebec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBEC 10796 bytes
SHA-256: c02d821e2dec183b6c2bf88e0d6cbbf820e2c823d52887af398a3d1ec5fac2cc