Malicious PDF — malware analysis report

Static analysis result for SHA-256 994a71ebd2fd7472…

MALICIOUS

PDF

79.9 KB Created: 2021-09-17 13:20:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: d99068f094fb02933f8be532d292734a SHA-1: 19da989dd5ca14c94ff36544997e2ad4226babe3 SHA-256: 994a71ebd2fd74724aa68e3fbe6e81990b7be326fc94c67c4dedee12c3656caa
96 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier strongly indicates maliciousness. The primary function appears to be a link farm, likely intended to redirect users to malicious sites or for SEO spam, rather than delivering a direct payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 https://laborke.ru/uplcv?utm_term=how+to+download+mini+militia+old+version PDF link annotation
    • http://scard.vn/app/webroot/uploads/files/27951434098.pdfIn PDF document text
    • http://jjkxmy.com/upload/files/202109092348245738.pdfIn PDF document text
    • https://mayxaydungthienlong.com/uploads/files/files/59204542754.pdfIn PDF document text
    • https://brtim.com/uploads/wysiwyg/files/61198488434.pdfIn PDF document text
    • http://turinimoti.com/assets/userfiles/file/wuxumijerozekaximekuzuke.pdfIn PDF document text
    • http://dakhoanhanai.com/images/files/dasaduj.pdfIn PDF document text
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/28pv9r304ev29603oav523vfh9/45866960984.pdfIn PDF document text
    • http://studiobaldizzone.com/userfiles/files/44753049015.pdfIn PDF document text
    • http://pet.nfe.go.th/m_site/ckfinder/userfiles/files/26724742649.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/76139915864.pdfIn PDF document text
    • https://myhoorayhealth.com/wp-content/plugins/super-forms/uploads/php/files/415c0e941a6aa70eaca1235a8ade693a/46667485518.pdfIn PDF document text
    • http://rewitex.pl/userfiles/file/webot.pdfIn PDF document text
    • http://nexxosrealty.com/userfiles/files/mabajomaw.pdfIn PDF document text
    • https://xtrafitcoaching.com/www/images/files/12970411516.pdfIn PDF document text
    • https://zemtechnika.lt/public/site/0files/90755663910.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/16141abd974e29---fomudewen.pdfIn PDF document text
    • http://3dprofi.net/images/uploads/file/97946301275.pdfIn PDF document text
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/635eab446d27a47415de6fc6646b229e/roxupobogowutibe.pdfIn PDF document text
    • http://heatherjansch.com/ckfinder/userfiles/files/xopexaluxituseg.pdfIn PDF document text
    • http://ducthanhtam.com/uploads/userfiles/file/nojunagoradupakiti.pdfIn PDF document text
    • http://szentistvanpatika.hu/upload/file/93442652287.pdfIn PDF document text
    • http://www.ecostroyservis.ru/File/1382058810.pdfIn PDF document text
    • http://zulassungsservice4you.de/bilder/file/gawujeko.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_off0000d2b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2B4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eacb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEACB 10552 bytes
SHA-256: 7e0be6f737fb2d65e1e4da838171f8d2437dbf181af6b1a29bbf8f269f935efc
font_02_sfnt_off000102d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102D3 18216 bytes
SHA-256: 8c78d6cab61468726c91d9adce11f4c2d3e80bb698149666d51bbb62014a74cc