Malicious PDF — malware analysis report

Static analysis result for SHA-256 21b678d2a580ab28…

MALICIOUS

PDF

84.8 KB Created: 2021-09-13 10:11:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 4770995decb8b1ccb8d7430d9669795c SHA-1: dfb4cede1a74d633bc8c179d67bd97ce6cc7af2d SHA-256: 21b678d2a580ab2808d103dbf637376062b8a832280585c3e873b36254296878
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF contains numerous links pointing to various domains, many of which are identified as disposable hosting or compromised CMS uploads, indicative of a link farm used for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent, aligning with the characteristics of a phishing or downloader campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • 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 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://canxetaidientu.com/images/file/83294085259.pdf In PDF document text
    • https://wheelmartthailand.com/image/upload/File/ximimazujalejezeb.pdfIn PDF document text
    • http://dichvuhangngay.vn/uploads/image/files/lidimejunuduzu.pdfIn PDF document text
    • http://specialcats.nl/media/files/34134209469.pdfIn PDF document text
    • https://interior-mark.com/ckfinder/userfiles/files/81099180215.pdfIn PDF document text
    • https://sunpower.lv/ckfinder/userfiles/files/67877026753.pdfIn PDF document text
    • http://1utilaje.ro/mm/file/raregenin.pdfIn PDF document text
    • https://12waktu.com/contents/files/rusuvegawizilazixozeparej.pdfIn PDF document text
    • https://agape4u.org/userfiles/file/wamojetosixefidutixexawit.pdfIn PDF document text
    • http://capthepcongtrinh.com/uploads/news/files/nigudaxog.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613e79f784292---97567928963.pdfIn PDF document text
    • http://spad.kr/userData/ebizro_board/file/tobipepazifolibif.pdfIn PDF document text
    • http://janaturismointegrato.com/uploads/file/18505865565.pdfIn PDF document text
    • http://www.euro-fly.eu/userfiles/files/95993178975.pdfIn PDF document text
    • http://kimandyoo.com/userfiles/file/17248372.pdfIn PDF document text
    • http://didongsinhvien.com/upload/files/mixabugevomefun.pdfIn PDF document text
    • https://slide-bearing.com/d/files/94474425103.pdfIn PDF document text
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/c06972ef9da30f6169d317f9fc2a7719/80440415454.pdfIn PDF document text
    • https://madspot.dk/ckfinder/userfiles/files/wuluxex.pdfIn PDF document text
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/982fa8bbbe63cd0840cda3b93b04ceb1/67909837299.pdfIn PDF document text
    • http://pes.edu.mn/ckfinder/userfiles/files/ziwozad.pdfIn PDF document text
    • https://letajicikoberce.cz/userfiles/file/54268136292.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16134278235124---84521223179.pdfIn PDF document text
    • http://miryangpension.com/FileData/ckfinder/files/20210905_D90697DF728A336B.pdfIn PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613ac8719866b---58036162152.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=moto+e5+plus+updatePDF 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_off0000e86c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE86C 17392 bytes
SHA-256: 494de66c093558379dbfc82ac88ef90d7a72f84414d354d432a10115b36baf67
font_01_sfnt_off000115f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115F7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012e0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E0E 10316 bytes
SHA-256: 69d272a2aa561a1ab3401ae7b0bb29137daa0514fa489eb57cd386cbe5bf5e49