Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ca8b407c3e8254c…

MALICIOUS

PDF

93.1 KB Created: 2021-07-04 07:26:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 3da45abaaf76ecece834608475e972de SHA-1: 6d77a84535d69f17e80bbdcfb7bc0214317ff4b7 SHA-256: 4ca8b407c3e8254c18c0cc1732979aff1a13bbd7aa406747a9281e8c93057068
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links pointing to compromised WordPress sites and disposable hosting, indicating a phishing or malware distribution attempt. The ClamAV detection and ML classifier strongly suggest malicious intent. While no scripts were explicitly extracted, the nature of the embedded links and the heuristic firings point towards a common pattern of using malicious documents to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9786

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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=not+even+emily PDF link annotation
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/d83064b3e82d4d7da4de3eb9a0785962/12130946850.pdfIn PDF document text
    • https://www.amiunaorchestra.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160cb446ca47b9---sewotawoje.pdfIn PDF document text
    • http://africansafaris-spain.com/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/lutimoduruzuvase.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16073a39c0c15d---kuduxon.pdfIn PDF document text
    • https://kham.vn/userfiles/file/jegipepubobemawabazi.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/gforf8mpadjtm5rpmf6s6d1n74/siruzegikafofam.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/ee3c44de030adf7c26a87faa4c1a2369/9183919132.pdfIn PDF document text
    • https://10kshot.com/customerinterview/ckfinder/userfiles/files/dakufunesojo.pdfIn PDF document text
    • https://marljivo.hr/UserFiles/files/56020889755.pdfIn PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/pv6ejk7p244bsdb3812bvmv292/2278628020.pdfIn PDF document text
    • http://www.leposeur.fr/site/upload/ckfinder/files/96660600049.pdfIn PDF document text
    • https://electrabicycles.pl/app/webroot/uploads/file/16216993971744.pdfIn PDF document text
    • http://unsersohn.ch/images/file/77925249647.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/8cc687afea90cd8bb2058aba0de818ce/dejepivaxofuriwamux.pdfIn PDF document text
    • http://katachizu.com/img/news/files/faneze.pdfIn PDF document text
    • http://dianacb.cz/userfiles/file/89075696286.pdfIn PDF document text
    • http://aloeverajuice.cz/files/file/69780525715.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/edc0003b8ea1756b851f67ed6a01a156/kefekosaxewipizi.pdfIn PDF document text
    • https://electroagro.es/pub/files/pologazupu.pdfIn PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/207d914a07e4b70e89fcef3c8f8ea9c9/zapavusuxukemomit.pdfIn PDF document text
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/e12aa322fcdf10ba9b4871f2fd333cd5/betipobepibomunijituf.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160886f6b110d8---kilelafe.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1607a2a3b51325---gokivad.pdfIn PDF document text
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a6b0cdc5a0a---jenid.pdfIn PDF document text
    • http://thunderstar.cn/userfiles/file/20210515091435350077973.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/zededar.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f1e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1E7 16368 bytes
SHA-256: 1957c7158e46d2a1fcea66bafa400ac9ebca94e16e515df6fcf3dbaa0e857b8b
font_01_sfnt_off0001083e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1083E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012054.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12054 9996 bytes
SHA-256: 7a91790cda06fdc25335d6c3fdb733aa6aef396b6b0ab918377ced71a40cf0ec
font_03_sfnt_off00013672.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13672 17800 bytes
SHA-256: 2491078a343b531633fe0c2004d36601d7878d1e165cdcc189c03b6d09e1d43d