Malicious PDF — malware analysis report

Static analysis result for SHA-256 687f9ff92ef0573f…

MALICIOUS

PDF

83.1 KB Created: 2021-09-16 08:26:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 07d2876b30a31c43a631e8b2cda4074c SHA-1: b8fc0760b9eec1e9dac4c88ca24cf7906cead0c6 SHA-256: 687f9ff92ef0573f09cad253704f4001e3b3b1d29d61bc3662293fd63229f0e1
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple external URLs hosted on potentially compromised or disposable domains. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM rules suggests an attempt to obscure the true destination or leverage compromised infrastructure for distribution. While no scripts were explicitly extracted, the nature of link farms in PDFs often involves JavaScript to facilitate redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://pixomot.ru/uplcv?utm_term=doctor+who+rose PDF link annotation
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/76580232545.pdfIn PDF document text
    • http://rapabzenec.cz/obrazky/files/kagarewofumivubuz.pdfIn PDF document text
    • https://www.akilciilacdernegi.com/ckfinder/userfiles/files/rudegamekijonifipafaf.pdfIn PDF document text
    • https://bringem.de/wp-content/plugins/super-forms/uploads/php/files/87f879c8e828b21fb89a4b913aee2ad9/54274512430.pdfIn PDF document text
    • http://polins.org/public/userfiles/file/juwewefolititikotimutike.pdfIn PDF document text
    • http://oresteruggiero.com/userfiles/files/87109989172.pdfIn PDF document text
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16142d1840da8f---25221032731.pdfIn PDF document text
    • http://magendans.com/imagefiles/file/14600574478.pdfIn PDF document text
    • http://brno-skoleni.cz/ckfinder/userfiles/files/44535567446.pdfIn PDF document text
    • http://www.americaninvest.net/upls/files/foseguxuxepadevaxuf.pdfIn PDF document text
    • https://flomogroup.com/upload/files/21285076897.pdfIn PDF document text
    • https://mywayrtk.com/userfiles/file/68299238381.pdfIn PDF document text
    • https://bocion.com/ckfinder/userfiles/files/rilajuwurexizorakala.pdfIn PDF document text
    • http://i-daa-wl.de/userfiles/pebuvukesudusetus.pdfIn PDF document text
    • https://lapakunited.com/contents/files/rimaxurenaveresoxuro.pdfIn PDF document text
    • http://makinsushi.com/uploads/files/wawevadaxexivitemulid.pdfIn PDF document text
    • http://mfcwestenkwartier.nl/beta/userfiles/file/jevanadapa.pdfIn PDF document text
    • http://bubb.cn/up_file/file/memamirix.pdfIn PDF document text
    • http://urs-certification.com/gais/image/file/12616988568.pdfIn PDF document text
    • https://rosycaffe.com/file/8749057483.pdfIn PDF document text
    • https://greshamgilessalon.com/wp-content/plugins/super-forms/uploads/php/files/3c4ab1d0ba5b0023f20244b6a5947b52/kidatenubewuzox.pdfIn PDF document text
    • http://ownlines.com/upfiles/file/60626350876.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/33a765626e2a3f9ddca2f98dce39b321/nisutirofanazakek.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_off0000e257.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE257 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fa69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA69 17944 bytes
SHA-256: 4364681a735003e092aee3ad9e656ba3fe93aa9c8ea56a18a8c6b0be821c8c01
font_02_sfnt_off0001288e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1288E 10008 bytes
SHA-256: 4ac1f10396d5f3734a63a11bff8992f579ffcc516511fa8468dea44655c60b0d