Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c8d98a9031cff21…

MALICIOUS

PDF

86.0 KB Created: 2021-07-07 00:01:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7bd84c60799f5cf755ba3a7980ef77d7 SHA-1: 7f15646f45dd9b2e934cf485d8b798f71ae37bc0 SHA-256: 5c8d98a9031cff21c5a46e00ecfde3fac5179af9b1431b2549991127c6f4ba77
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm containing numerous external URIs pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. The document body is heavily obfuscated and unreadable, providing no direct content clues.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://inwebjor.ru/uplcv?utm_term=gas+a+is+more+soluble+in+water+than+gas+b+at+the+same+temperature
    • https://digireg.ch/upload/fipovigikanoriweda.pdf
    • https://hopefor.today/wp-content/plugins/super-forms/uploads/php/files/edfa66812ebf9c82a74a1cb9929e1ed1/51683192448.pdf
    • http://sosnovgeo.ru/userfiles/file/xuwoxexetezuwarerosugu.pdf
    • https://egokituz.eus/files/galeria/files/bizuwomixazebufozusemup.pdf
    • https://www.travelticket.com.au/wp-content/plugins/super-forms/uploads/php/files/he05fuvs0e4v791j91gqb065um/durisuvinugatironom.pdf
    • http://beulahcooleycollection.com/clients/870349/File/89204397112.pdf
    • http://coxfamilyreunions.com/clients/5/56/566bc9ad745482f371977770c3e6b383/File/98314515168.pdf
    • https://www.straightmyteeth.eu/wp-content/plugins/super-forms/uploads/php/files/34c88d1b9a4f7b4097b7cc6eae743d5a/timedage.pdf
    • http://p-itos.net/admin/userfile/image/file/29601865013.pdf
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16098762251c76---filibumefenuvokof.pdf
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/r2pg75vtf14qs3cbgd6hevkrpu/73776196839.pdf
    • http://influences-vegetales.eu/assets/Image//files/vubibepagumadiwi.pdf
    • http://sity-luxe.ru/userfiles/file/wapulugivowazarusetevosas.pdf
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606f05451327b---24220869081.pdf
    • http://businessplan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/75006148117.pdf
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608a572878f3e---safiretux.pdf
    • https://razvozka24.ru/wp-content/plugins/super-forms/uploads/php/files/df3362b8056442d276e35be8301c1f4f/famegajemapibe.pdf
    • http://zabradli-znerezu.cz/userfiles/file/gabilira.pdf
    • http://guides2alpes.fr/uploads/file/39458233464.pdf
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bdec641dfba---rizevi.pdf
    • http://boschvietnam.vn/files/usersfiles/files/27139744936.pdf
    • http://akkoryazilim.com/userfiles/file/60391509116.pdf
    • https://www.drmarlenebothma.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160cfafe5a2b74---levekodubukizupusun.pdf
    • https://www.bakirkoytemsilcisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078c70b9f354---47460338953.pdf
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/c1aon310ifajm14sf99imtb4k0/xuridinosovilosopixuso.pdf
    • http://azizolace.cz/images/file/tadisadiw.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_off0000eae8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEAE8 16792 bytes
font_01_sfnt_off000102ff.bin
5d75656cc524f01b767fa3a36c0f0319fa2b495f61b33204409402af672e63e4
pdf-font-stream PDF embedded font (sfnt) at offset 0x102FF 11064 bytes
font_02_sfnt_off00011c72.bin
813c75023f54fc58199843b1457c179fc33e7d4e6e5b5a3b1b683b5d321c92ce
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C72 17568 bytes