Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a135447c4808e1b…

MALICIOUS

PDF

77.5 KB Created: 2021-09-27 22:00:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 794b8c36aa05eea231d6dce0f0b05f83 SHA-1: 614797193eed5f67fa450ce6f278022b55f2af10 SHA-256: 4a135447c4808e1b16362ffff205ccec36194f3ae090acf40c4fa6e06d54eaf1
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external URIs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://queure.ru/uplcv?utm_term=history+of+the+necronomicon+pdf
    • http://felixefontesadvogados.com.br/ckfinder/userfiles/files/vuwaterudufipameki.pdf
    • https://toptenstudy.com/upload/files/BodyFile__613F47EF3E9FA.pdf
    • http://www.guus.edu.mn/ckfinder/userfiles/files/taxorokuvu.pdf
    • http://papaicountrylodge-longstay.com/user_img/files/refabupupuvomemajopobovub.pdf
    • http://cdseoulps.com/uploadfile/fckeditor/file/zinevezexajiru.pdf
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b2cf3eb1b6---11144332406.pdf
    • https://soudurelauziere.com/upload/editor/file/91699600971.pdf
    • https://confidence-ist.mktechsol.com/ckfinder/userfiles/files/52997548098.pdf
    • http://radissonhoteltraining.com/userfiles/file/77853784578.pdf
    • http://tantos.jp/js/upload/files/35900329466.pdf
    • https://goooinggroup.com/userfiles/files/20210921_064842.pdf
    • https://doitsolutions.co/wp-content/plugins/super-forms/uploads/php/files/3750a76424f8c2bc6be8280f03fd7178/finovusabekilowopujubava.pdf
    • http://afslab.asia/upload/files/gofolikagalijitatuluzufa.pdf
    • http://messtores.ca/fck_user_files/file/51183911490.pdf
    • http://kolaykanal.com/userfiles/files/46908697736.pdf
    • https://dubaimotorcycletours.com/uploaded_images/files/muxatit.pdf
    • http://chinawin-consult.com/userfiles/kogagepomofibogoliro.pdf
    • http://forter.vn/hinhanh/file/51550332180.pdf
    • https://successstudio.net/userfiles/file/25553557731.pdf
    • https://fengshan-zhennangong.org/upload/ckfinder/files/30214609838.pdf
    • http://sofia-es.tokyo/yamituki-n/uploads/files/10391138253.pdf
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/ae00c95abe99dad1e17ff7bcc8514ba0/gaserewolatu.pdf
    • http://carbontuning.ru/file/paxawezivefuvoxabof.pdf
    • https://vanchuyenduongsat.vn/upload/files/8035196769.pdf
    • http://umhouses.com/uploads/files/13826016329.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c288.bin
5796f5489ab7f1da81e9d5d48719c6a93343cb6293191a82f1955ec782214156
pdf-font-stream PDF embedded font (sfnt) at offset 0xC288 20080 bytes
font_01_sfnt_off0000f746.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF746 16792 bytes
font_02_sfnt_off00010f5d.bin
333fd173f964db77c26c4d0ede46efca1c1896acf92a4613b786e61eca5847ff
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F5D 10780 bytes