Malicious PDF — malware analysis report

Static analysis result for SHA-256 51515bb729bcad85…

MALICIOUS

PDF

81.7 KB Created: 2021-08-16 09:21:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: b71cfafbd5cb87db3604c6021ec4b046 SHA-1: 9daa87f92b78e8407ba19a907ac1586d9ec8946d SHA-256: 51515bb729bcad85c42f084fa5a3bb0c58081ad02a97341f7f7be0613d23b85c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged as malicious by a machine learning classifier and ClamAV. It contains numerous links, many pointing to compromised WordPress sites, suggesting it functions as a link farm. The presence of multiple distinct hosts and the use of 'utm_term' parameters indicate an attempt to direct users to potentially malicious or phishing websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a5ff7d20640---gewadavo.pdf In PDF document text
    • http://pvsystreports.com/wp-content/plugins/super-forms/uploads/php/files/kck2hkj612akih6nhqtaco8ce4/46901837640.pdfIn PDF document text
    • http://tokyoto.pl/UserFiles/file/23849453645.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16094ddac5171a---90479143360.pdfIn PDF document text
    • https://rabudiagnostic.com/userfiles/files/xudekadupipopanelowom.pdfIn PDF document text
    • http://elskenecologie.nl/files/sekop.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/16075e9deae0d3---wotoxoka.pdfIn PDF document text
    • https://africanresearchcenter.com/userfiles/file/94589984298.pdfIn PDF document text
    • http://ckrestaurantgroup.com/ckfinder/userfiles/files/61763094345.pdfIn PDF document text
    • http://hyundai-dongdo.vn/images/files/9896675797.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/magajuzozan.pdfIn PDF document text
    • https://fiberglasssupplydepot.com/userfiles/file/kasiwoji.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f3d172f2e3---zapuxuwapiposulakenib.pdfIn PDF document text
    • http://andrenickels.de/ckfinder/userfiles/files/77915192294.pdfIn PDF document text
    • http://quick-thailand.com/images/uploads/file/nesejilogomazomov.pdfIn PDF document text
    • http://fusen-es.info/yamituki-n/uploads/files/pefonibuvuxagi.pdfIn PDF document text
    • http://kstarsmall.net/userfiles/file///xilabixi.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/76858b3ac178ac164924771adf9a8fb8/53617468537.pdfIn PDF document text
    • http://apexhealthnutrition.com/newerac2c/userfiles/file/nafozepokotatikapolez.pdfIn PDF document text
    • http://termocity.by/pics/files/88171273286.pdfIn PDF document text
    • https://carcarnet.com/home/sandbox/domains/hkdance.tritek.hk/public_html/ckfinder/userfiles/files/11358374017.pdfIn PDF document text
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f71dc1e027---34624481807.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=epsa+brazilian+blowout+instructionsPDF 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_off0000dc0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC0D 10604 bytes
SHA-256: fed1a1673fb7279607807977985bfe6816c3e98fecdfaff3187900a75f2508d2
font_01_sfnt_off0000f444.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF444 17044 bytes
SHA-256: fa0a3becb13f04e5d8bca2889034c40037755cf09c4b404edcc8c441b0d35e0a
font_02_sfnt_off000120fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120FA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1