Malicious PDF — malware analysis report

Static analysis result for SHA-256 b55cf4d632d06807…

MALICIOUS

PDF

81.3 KB Created: 2021-09-16 09:47:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 6e654d7bedd8047299fc7d2e5e8ce58e SHA-1: 9335a5d1c0266cdc5d91e579dcb365a93b7e6251 SHA-256: b55cf4d632d068078cb9a644d5548776689af74f42366776f6cdf0ade3175558
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed for malicious redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. The presence of external URI heuristics and link farm indicators further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://mayxaydungthienlong.com/uploads/files/files/viriraz.pdf In PDF document text
    • https://ylwlgwadmin.ylwl.cn/upload/files/gizevozowofaxominoxefiz.pdfIn PDF document text
    • https://adian.eus/files/galeria/files/fawazinazuxofonago.pdfIn PDF document text
    • http://www.louisefarmersmith.com/admin/ckeditor/ckfinder/userfiles/files/xinisisuviluti.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a0d95ebf89---kopimisutisabivutobe.pdfIn PDF document text
    • https://cailux.lu/userfiles/files/lugizuv.pdfIn PDF document text
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/161371f4f1128c---11758616976.pdfIn PDF document text
    • https://geya99.com/ckfinder/userfiles/files/96398054743.pdfIn PDF document text
    • https://nobelboya.com/userfiles/file/janajukoxusunobexikizuje.pdfIn PDF document text
    • https://electrodomesticaruano.com/images/ckfinder/files/35999775582.pdfIn PDF document text
    • http://czerwoneiczarne.pl/files/file/wavewonadudoni.pdfIn PDF document text
    • http://tms-technology.com/ckfinder/userfiles/files/resebizedipo.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/7af81e8c746e0713626c7bfaeb50b76a/4252198482.pdfIn PDF document text
    • https://alutat.com/data/file/74813122017.pdfIn PDF document text
    • http://robbes.nl/media/files/9565997940.pdfIn PDF document text
    • http://dxqzx.com/ckfinder/userfiles/files/20210909_214845.pdfIn PDF document text
    • http://phutungtdc.com/upload/files/46755511193.pdfIn PDF document text
    • https://enilubricantvn.hoakhanh.vn/uploads/image/files/52679332716.pdfIn PDF document text
    • http://superlitefan.com/uploads/files/tijumifuvilutaroborana.pdfIn PDF document text
    • http://vecsecity.info/editor_up/badanexero.pdfIn PDF document text
    • http://sure2trips.com/bot/ckfinder/uf/files/jasatusidemiwafukazibedo.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/77859916887.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=pubg+hack+online+generatorPDF 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_off0000d9f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9F8 10672 bytes
SHA-256: eed45e490c12fc73ed099259211dde44f3ee543bc7cec97ac240f42ea3770172
font_01_sfnt_off0000f25e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF25E 17908 bytes
SHA-256: f23ee391fb920f381f9c459b5c76d68fd0648b9e97be65f02dc821cac9fa21a7
font_02_sfnt_off00012002.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12002 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1