Malicious PDF — malware analysis report

Static analysis result for SHA-256 c585387f120340e4…

MALICIOUS

PDF

83.5 KB Created: 2021-09-09 22:14:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: cc18e73acecdf3ebe4340aed6901e24a SHA-1: e9f700415b9716a73dbe35d7f800519e469ab9dd SHA-256: c585387f120340e440a619707bac13a82780cee10db53ee81ac5dd3ccc960222
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to domains flagged as compromised CMS uploads or disposable hosting. The ML classifier strongly indicated maliciousness. While no scripts were extracted, the structure and URL distribution suggest a link farm designed to manipulate search engine results or lead users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://aquaclub.hu/userfiles/file/73738302275.pdf In PDF document text
    • http://j1ent.com/userfiles/file/20210908031012.pdfIn PDF document text
    • http://ehomerealestate.org/images/file/nanirufowenewokaji.pdfIn PDF document text
    • https://egc.ecrom.work/syo/files/51776373421.pdfIn PDF document text
    • http://dhf-china.com/d/files/75355221917.pdfIn PDF document text
    • http://80tner.friend-match.com/upload/files/82340341861.pdfIn PDF document text
    • http://studiosaletta.it/userfiles/files/56531651020.pdfIn PDF document text
    • http://uforoi.com/app/webroot/uploads/files/jakufutopirog.pdfIn PDF document text
    • http://www.dfdtrading.sk/ckfinder/userfiles/files/10419060040.pdfIn PDF document text
    • http://szjwwj.com/userfiles/file///rikenow.pdfIn PDF document text
    • https://www.loisirs-auto-occasion.fr/ckfinder/userfiles/files/3016569237.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137c714e059d---41945020475.pdfIn PDF document text
    • http://jpind.pl/userfiles/file/selapotiseb.pdfIn PDF document text
    • https://afgventuregroup.com/cfiles/file/91378728464.pdfIn PDF document text
    • https://rubenoferro.com/userfiles/file/50623143896.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613809aad4e42---zamajekakixatiz.pdfIn PDF document text
    • http://sm.ac.th/ckfinder/userfiles/files/xarebanonawoxujuwoje.pdfIn PDF document text
    • https://kalashad.com/userfiles/file/badubomefugoxadadidor.pdfIn PDF document text
    • https://gulfcans.com/home/madarmun/public_html/gulfcans/images/bulk_images/files/kerizuwejozozovoxigokad.pdfIn PDF document text
    • http://studiocommercialedelpiano.it/userfiles/files/4423377222.pdfIn PDF document text
    • https://doucetplasticsurgery.com/ckfinder/userfiles/files/kewezela.pdfIn PDF document text
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/d39cc1c942c755da2b870a30ffaa3f8d/32473253602.pdfIn PDF document text
    • http://studiolegaletrotta.eu/userfiles/files/sokajefovefapovaroso.pdfIn PDF document text
    • http://ahnil.com/userData/board/file/51882956025.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=best+free+aso+toolsPDF 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_off0000dfe1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFE1 18952 bytes
SHA-256: aefe5f728ba034ab2fd40679d011a6ed8c9131925106779aea6905a4fbf82f63
font_01_sfnt_off000111ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111EA 10064 bytes
SHA-256: 59528e05089c87133a15426a0457d087ad15e91af6f12023634d51f076f0a76e
font_02_sfnt_off00012888.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12888 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1