Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1f5681a53b94b24…

MALICIOUS

PDF

72.5 KB Created: 2021-09-02 12:30:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 4f7e39f92934f44e3457c3ed0a81c554 SHA-1: e9e375d46c631c21f4576e8debfd7c3fcc5ef112 SHA-256: c1f5681a53b94b2442e6ad2692e93ec0aee0fe6dd2b36a27810c85242d104480
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The document contains numerous links to external websites, many hosted on compromised WordPress sites, suggesting it is part of a link farm or phishing campaign. The primary URL, 'https://drafthe.ru/uplcv?utm_term=medical+histology+lecture+notes+pdf', is presented as a search result, likely to trick users into visiting a malicious site for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 https://drafthe.ru/uplcv?utm_term=medical+histology+lecture+notes+pdf PDF link annotation
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad8a6cbd736---43923663668.pdfIn PDF document text
    • https://mygamedaysports.com/wp-content/plugins/super-forms/uploads/php/files/6ea296a1acac5c2cad10db3ed69099bb/66832199976.pdfIn PDF document text
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/e09ef79c0e3b621f788bbf1e52490633/79001774790.pdfIn PDF document text
    • http://opakowania-loga.pl/zdjecia/fotki/file/60357144131.pdfIn PDF document text
    • http://np-laser.com/upload_fck/file/2021-6-18/20210618022126136797.pdfIn PDF document text
    • http://www.oneworldkarate.com/fckeditorimages/userfiles/file/tidikidikun.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/1stolresbucslmn5mq49uk7hg2/pilul.pdfIn PDF document text
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/6c46f147e82c5c75dce8a0b0510400d8/xutukunekusewokanifa.pdfIn PDF document text
    • http://citadelcaralarms.com/userfiles/file/17928776015.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16088341552b60---72550564168.pdfIn PDF document text
    • https://estduquebec.com/scripts/php/xenocode/lib/ckfinder/userfiles/files/wadinajobejilufojiminaje.pdfIn PDF document text
    • https://leesman.com/wp-content/plugins/super-forms/uploads/php/files/62d8b082d3ea4572e0c25682ceafd34c/xubaxekiwedo.pdfIn PDF document text
    • http://girc.ncue.edu.tw/ckfinder/ckfiles/files/taxug.pdfIn PDF document text
    • https://agatanorek.com/files/file/72670885913.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090dc44cc847---rebepidajutolimigexodekej.pdfIn PDF document text
    • http://vijyaiprismcrm.com/userfiles/files/degopi.pdfIn PDF document text
    • http://korea-seals.com/ckfinder/userfiles/files/vanexegugumariw.pdfIn PDF document text
    • http://kotolantopeni.cz/file/4924825234.pdfIn PDF document text
    • http://hsound.ro/images/custom/file/50975402291.pdfIn PDF document text
    • http://granitemountainranch.net/userimages/makiberazofixosolo.pdfIn PDF document text
    • https://lamthong-marchph.com/piceditor/file/19412048831.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aadd873920b---gisakujo.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/feb36dd2b85c1d6e02237198a9662935/38087025253.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_off0000b9f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9F2 11108 bytes
SHA-256: 818355859d5269cb0ebd84ed69c2edc2e833bc836a25321b06fc8d65b718734f
font_01_sfnt_off0000d39b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD39B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ebad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBAD 16004 bytes
SHA-256: fd72aff5a8c941f64fdf7a0fde7c377befa01ba5a0943d4db2398bea64e2693c