Malicious PDF — malware analysis report

Static analysis result for SHA-256 51d6c6ce489cbbc0…

MALICIOUS

PDF

86.1 KB Created: 2021-07-09 13:14:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 41f169f7de338e7cdcb40c3cf8914af5 SHA-1: bd2d33944b2bbf2bacbf8313c77e6576e3a679b9 SHA-256: 51d6c6ce489cbbc02debf8efa41baf36e4ce65ea81016f97917b4e9b153607bc
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous URLs, many of which are hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple links on potentially compromised infrastructure suggests an attempt to obscure the final destination or leverage existing vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

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://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/04aj4sas4nsgc4amhqalf7gd1h/75953210664.pdf
    • http://lbs.ac.at/wp-content/plugins/super-forms/uploads/php/files/l364udp7ilaff1nd375goanljc/fabelavawipe.pdf
    • http://banphimchuot.com/userfiles/file/zepotipet.pdf
    • http://speaklifeiamgreatness.com/files/files/54156441485.pdf
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/c30ebb911ae12d02b2a0d3c95ae090ad/70222165990.pdf
    • https://higher-reason.com/wp-content/plugins/super-forms/uploads/php/files/e398glgd6m3lok4gm0vopl0m3e/jogevewexo.pdf
    • http://hocikto.info/userfiles/file/76465075640.pdf
    • http://www.asslar.de/downloads/kilotukaz.pdf
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/160d4a8cfa6bf0---35267703899.pdf
    • http://lbs.ac.at/wp-content/plugins/super-forms/uploads/php/files/9dbmo1cf0s98arvcltugcfnr4e/4005578686.pdf
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160781510538a8---dofuxelepiwe.pdf
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/1609c9c31d6a6f---72681504966.pdf
    • https://alshamiltrading.com/alshamilfiles/file/ruvipavibomewu.pdf
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070c448cfe24---42343480833.pdf
    • http://architettipassarinmarzotto.com/userfiles/files/xelobujesix.pdf
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dfccc228b36---38184762050.pdf
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/160db6ddbcab8e---pebevunovuxenazibe.pdf
    • http://qlinairnv.be/userfiles/file/noxiwajibobubexizer.pdf
    • http://abwingssuffolk2.com/uploads/files/liredapideda.pdf
    • http://fszhenjia.com/upfolder/e/files/20210610170159.pdf
    • https://wccia-vastu.com/wp-content/plugins/super-forms/uploads/php/files/0c8efe5ccf1d34f6e71f2af5134f5325/wexekilubinegiwi.pdf
    • http://ubest.ru/images/file/70834687808.pdf
    • http://kimbuunguyen.com/uploads/userfiles/file/jubifatamisexusozumu.pdf
    • https://www.kbstephens.com/wp-content/plugins/super-forms/uploads/php/files/cb4d538ca232e2fcc4bb66b0a6e05c03/dibelabivelulezegikixa.pdf
    • https://heykidsletscook.info/wp-content/plugins/super-forms/uploads/php/files/55b7e5ddcf05b9a2983a0a5aa474be52/64826521011.pdf
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b42e5f4dc0c---besigosiguki.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=last+in+first+out+inventory
    • 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_off0000efe2.bin
730c69d47ee6ef2b8a0acb279ea40c683945775535511e76c40feb231eb39550
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFE2 16692 bytes
font_01_sfnt_off00011b15.bin
d7f3ac7b7941dccdac9e015c1a11a8407f5c08640499f899007a9634eb6a003d
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B15 10396 bytes
font_02_sfnt_off000132d8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x132D8 16792 bytes