Malicious PDF — malware analysis report

Static analysis result for SHA-256 91242f6f3c28b073…

MALICIOUS

PDF

95.2 KB Created: 2021-09-21 20:53:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 278027a99128783771919cfd421cbddf SHA-1: 274ccaa335442291fd40a98b7e879b391ffd641b SHA-256: 91242f6f3c28b073c5bdd93683b7c249eb10b87b059c053f049d513e9f8cecd8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to compromised or disposable hosting sites, suggesting a link farm used to redirect users to malicious content. The presence of external URI heuristics and the compromised CMS upload link farm strongly support a phishing or malware distribution attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://krusomying.com/data/file/nisoko.pdf In PDF document text
    • https://maurinet.com/userfiles/file/tabenatosidojesewix.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613423aabd2f6---nitelawaguzisuxezidel.pdfIn PDF document text
    • http://fabrikando.com/cmsimple/images/file/lexalewisewuboxose.pdfIn PDF document text
    • https://successstudio.net/userfiles/file/pobapimewag.pdfIn PDF document text
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16132bed7e970e---buzuri.pdfIn PDF document text
    • http://srmtteaparty.com/uploads/files/202109021806319712.pdfIn PDF document text
    • http://gaestehaus-am-erlkoenig.de/img/editor/file/besozidinibiwiresolibam.pdfIn PDF document text
    • http://isvpro.com/custom/files/57932853165.pdfIn PDF document text
    • http://stisk.com/file/1341385415.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c0ccf52a0e---76006440234.pdfIn PDF document text
    • http://abcbyspu.com/ckfinder/images_store/files/14692095660.pdfIn PDF document text
    • http://thesprotia.gr/uploads/file/47911342176.pdfIn PDF document text
    • https://wfca-czech.cz/temp/userfiles/files/65160838205.pdfIn PDF document text
    • http://na3.it/misc/file/57577128445.pdfIn PDF document text
    • https://larrialdiak.es/files/galeria/files/18291434528.pdfIn PDF document text
    • https://illustrations.noche.fr/images/files/93918620896.pdfIn PDF document text
    • https://tele-video.ru/upload/files/sojuzivijevuxolod.pdfIn PDF document text
    • http://cdn.eagle.mn/uploads/userfiles/files/jetixe.pdfIn PDF document text
    • https://luminex.pl/upload/file/gewuluvobuzebotujumano.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16147f7d223784---53033059213.pdfIn PDF document text
    • https://franchiseharbor.com/files/files/batimilanafefin.pdfIn PDF document text
    • https://radekslodkiewicz.pl/files/file/kavivekikejoz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=jelly+bean+sdk+versionPDF 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_off00010d14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D14 10548 bytes
SHA-256: 6ef79e0358e09800d16a9bb249e66826e290dcf1f7ba756634f7b0f7c2e535fe
font_01_sfnt_off0001253f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1253F 19344 bytes
SHA-256: 5f875a00605990815a37096bbe9670d23de2926237542e57e960639982c8f13d
font_02_sfnt_off0001576d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1576D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1