Malicious PDF — malware analysis report

Static analysis result for SHA-256 2cd391b44769e8e9…

MALICIOUS

PDF

70.0 KB Created: 2021-10-04 00:06:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 03f8031db05b7c0841942a4d57075a00 SHA-1: 71d7bb1cbcc64ef7f467568cfa19d77f0afc0753 SHA-256: 2cd391b44769e8e9b4fb19b6a894a5f6e2398244707abc24b266fe941df3abbd
126 Risk Score

Malware Insights

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

The sample was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, containing numerous external URIs pointing to potentially malicious content. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further suggests a deliberate attempt to obscure the true destination through a large number of distinct hosts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9837

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 http://baltic-rt.ru/ckfinder/userfiles/files/12261080260.pdf In PDF document text
    • https://smilaxlabs.com/userfiles/files/62745346306.pdfIn PDF document text
    • http://daehnfeldt.com/userfiles/file/videfasisupitakewepuli.pdfIn PDF document text
    • https://gym-rectif.fr/ckfinder/userfiles/files/kilidabefaba.pdfIn PDF document text
    • http://air-ned.com/uploads/files/wuxugosagojami.pdfIn PDF document text
    • http://tao-ssct.org/data/upload/file/4456837283.pdfIn PDF document text
    • https://dragonexpressml.com/userfiles/files/74652167707.pdfIn PDF document text
    • http://manegedebuitenwijck.nl/uploads/file/rumixefenekekipivetad.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1614c6fd504132---rupamulodojo.pdfIn PDF document text
    • http://studiomilano.eu/userfiles/files/19857332278.pdfIn PDF document text
    • http://philipsphotographystudio.com/3057945996.pdfIn PDF document text
    • http://wych123.com/upload/files/82373759543.pdfIn PDF document text
    • http://itnetworkconsultingsf.com/helpdesk/app/webroot/img/userfiles/files/wupuzeb.pdfIn PDF document text
    • https://toskov-yordanov.com/userfiles/file/vupexubebu.pdfIn PDF document text
    • https://gabconstruction.com/ckfinder/userfiles/files/89236913729.pdfIn PDF document text
    • http://retailcop.ca/files/rorewib.pdfIn PDF document text
    • http://strandedtattoo.net/file/76777599652.pdfIn PDF document text
    • http://bayernglobal.de/userVZ/file/82241786810.pdfIn PDF document text
    • http://debten.net/UserFiles/File/badobip.pdfIn PDF document text
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/50911309e4ece88981cdcfc051ec8d0c/ganogi.pdfIn PDF document text
    • https://laptoptranganh.com/data/dulieu/files/73602543200.pdfIn PDF document text
    • http://p-energo.ru/content/file/bimomibifirabuse.pdfIn PDF document text
    • https://clifestyle.net/uploades/userfiles/file/40525715039.pdfIn PDF document text
    • https://khmernative-rice.com/userfiles/file/fesataruv.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/fivimugesakevi.pdfIn PDF document text
    • http://ggmtc.net/userfiles/files/67106004755.pdfIn PDF document text
    • http://krr-nfe.com/suratnfe/UserFiles/File/55832450585.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=present+perfect+usePDF 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_off0000b24a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB24A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA5C 16432 bytes
SHA-256: 24d346f60932f7189102f75f86792e93b5b1e1b694eff44a54954cd7510608a2
font_02_sfnt_off0000f3ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3CE 10156 bytes
SHA-256: e8bf85bc393237d6c947025553b580f6cdd3917dd3ef7c96f7c33b6ffb619dea