Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b9804c3a7d76884…

MALICIOUS

PDF

81.6 KB Created: 2021-09-03 06:51:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 9f7d90058475cb8e5a94a44dda54c8b4 SHA-1: 8bb19a7f1afa068daeb30bbd7f39cbfd2960ea2b SHA-256: 3b9804c3a7d76884f10e9d130a2238a00b89ee94b9dc1a2e7c51cb3a204977e7
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many of which point to compromised CMS upload directories or disposable domains, indicating a link farm designed to lure users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://biirbeh.mn/images/content/file/lokesatixubisibibavegixaz.pdf In PDF document text
    • https://aadhaarretail.com/administrator/imagetemp/file/lubexipigajav.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/16088243477c97---8527482610.pdfIn PDF document text
    • http://akgikorea.com/file_upload/fck_upfile/file/86970208885.pdfIn PDF document text
    • http://www.lavalledesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608788bea6896---disakalipevadixu.pdfIn PDF document text
    • https://hideab.se/tc/Mediagalleri/file/rotexitirikeje.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606f30d1c308e---67588226925.pdfIn PDF document text
    • https://www.propertyfilevault.com/wp-content/plugins/super-forms/uploads/php/files/5aacaeddccefba7c63a4f788a830c5f7/5692702866.pdfIn PDF document text
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/12a798b512c94c4a06bdecbd0b5ede90/36944685409.pdfIn PDF document text
    • http://teplolux72.ru/upload/file/29705022282.pdfIn PDF document text
    • http://nacnsuaa.com/clients/4/49/49ab1acc6c62b5a39110d621a19f71c0/File/dedejaxiv.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/161057bb503951---76871941829.pdfIn PDF document text
    • http://worldprint.su/userfiles/file/4206102845.pdfIn PDF document text
    • http://dynamic1984.com/user_file/file/girizegukos.pdfIn PDF document text
    • http://namthangbasaltstone.com/uploads/image/files/loripideredazenubita.pdfIn PDF document text
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/qgspkujnhf5ot01nbcqmq0k1ep/68755368082.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/89dd430266aa694d9b22f497360a610f/vukedejuvobebuka.pdfIn PDF document text
    • https://www.azulejositurry.com/wp-content/plugins/super-forms/uploads/php/files/pj3g8megvtatscpg8c1ttplq14/kevopidulafu.pdfIn PDF document text
    • http://esoftland.com/userfiles/file/buwaduxolup.pdfIn PDF document text
    • http://myxroad.com/upload/userfiles/file///48996243277.pdfIn PDF document text
    • http://arqing.es/ckfinder/userfiles/files/vikoberix.pdfIn PDF document text
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/d4h33e0npev36m16slqf256v01/98524914212.pdfIn PDF document text
    • https://brod-plovdiv.com/images/dilemufubas.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cf205ae5f56---powikemu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=scala+tutorial+book+pdfPDF 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_off0000d891.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD891 10616 bytes
SHA-256: 9439e694d6f06d2fe9c7c9f00e8fffd5b144bb438ee02eb0a9880743a043f99e
font_01_sfnt_off0000f0b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0B6 17968 bytes
SHA-256: 1318d3e807621c82252f3f3abacb7612ebc9c466b90e12c45108a4be630f1616
font_02_sfnt_off00011f36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F36 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1