Malicious PDF — malware analysis report

Static analysis result for SHA-256 7f9accbfdfd2c4f1…

MALICIOUS

PDF

80.3 KB Created: 2021-09-21 11:15:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 8bddb035e5d6204099ea4c161c768e7b SHA-1: 49a67ef13c0a0f185138c8da9d671f92c3b8ff1f SHA-256: 7f9accbfdfd2c4f1dfb94b7775aac50bd4ca3f0244fbdb81596313e03e685db3
126 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. The document contains a link farm with 30 distinct hosts, many of which redirect through UTM parameters, suggesting an attempt to lure users to download potentially harmful files. The presence of numerous unknown URLs further supports this phishing and malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nikosdimos.gr/userfiles/file/37025672254.pdf In PDF document text
    • https://gym-rectif.fr/ckfinder/userfiles/files/56895534321.pdfIn PDF document text
    • http://busangh.com/attfile/fckimg/file///20210910132633_385078324.pdfIn PDF document text
    • https://familienbilstrup.dk/userfiles/file/33483710603.pdfIn PDF document text
    • http://gzperson.com/uploadfile/files/38879541747.pdfIn PDF document text
    • http://entryexpress.online/chapter_images/files/42045965251.pdfIn PDF document text
    • http://npcbalkan.net/ckeditor/ckfinder/userfiles/files/61130611218.pdfIn PDF document text
    • http://hungbuloon.com/media/ftp/file/xagudiz.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/42127910323.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/8u2ceumh9k39hfpqbr7n9isik5/sixub.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/161408c2535e01---2788643766.pdfIn PDF document text
    • http://hotelrefah4ter.ir/basefile/hotelrefah4terir/files/vugofuweratalalutajufumix.pdfIn PDF document text
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/ba14e871d5bdcf9d88e3d35c529d5cb6/86933957231.pdfIn PDF document text
    • http://twtipa.com/upfile/files/2021/09/01/24417615973.pdfIn PDF document text
    • http://imobiliariaimperio.com/files/files/55554396397.pdfIn PDF document text
    • http://yalcinsezer.com/upload/ckfinder/files/55170756578.pdfIn PDF document text
    • https://3eyamaichi.com/upload/ckfinder_temp/files/20210913193625.pdfIn PDF document text
    • http://kozelskadm.ru/files/uploads/files/9309441573.pdfIn PDF document text
    • https://mystruggle.uk/indigo/ckfinder/userfiles/files/93711324765.pdfIn PDF document text
    • http://baozhaopharm.com/upload/files/22044742513.pdfIn PDF document text
    • http://live-net.it/file/gajux.pdfIn PDF document text
    • http://trunghungplastic.com/luutru/files/nirulimekusosuviwemerosut.pdfIn PDF document text
    • https://volnynaklad.cz/data/file/96846705999.pdfIn PDF document text
    • https://karinbentum.nl/uploads/file/51644406301.pdfIn PDF document text
    • http://stefani.cz/fck/file/91874058461.pdfIn PDF document text
    • https://tsafar.ir/basefile/tsafarir/files/12381959425.pdfIn PDF document text
    • http://fapannimario.it/userfiles/files/vaxaxexaketabiw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=app+installer+androidPDF 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_off0000d810.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD810 10368 bytes
SHA-256: 62a644b55cc92b57c640648ecfc21d38480652bce44739c79e2fde9c531ad140
font_01_sfnt_off0000ef9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF9E 17228 bytes
SHA-256: 849370e499aaf02408f68dfca527a6ff92aee7438b40ff4eca35d8c3d2f02257
font_02_sfnt_off00011bf7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BF7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1