Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c9e81fc0210e70d…

MALICIOUS

PDF

75.6 KB Created: 2021-07-03 21:25:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: fad6eefe0b5c95010908dc602a274d49 SHA-1: 92be85322f440169b086078e9a589d2efae76372 SHA-256: 4c9e81fc0210e70d5761a20e73bb47647087f1c6f4bc9847311247e72d9668b8
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to websites that appear to be compromised CMS installations, specifically WordPress sites using form plugins for file uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of multiple distinct hosts and the structure suggest a link farm designed to obscure the ultimate destination or to leverage compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://refour.eu/wp-content/plugins/super-forms/uploads/php/files/2b22aedb5b25b06e33dd7ce93d8c81a9/73217255758.pdf In PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/16083aa5346d9b---sunalepogunaru.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/731b901b0827225f1c321ab9be65d966/berikogiwezatazigedire.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609cc05296bee---gamisu.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2bcba6b4f5---ruzepoxezovoribegawi.pdfIn PDF document text
    • https://www.hemoroidklinigi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b41f0acf4a---37523204124.pdfIn PDF document text
    • http://verduciautodemolizioni.it/userfiles/file/50752501683.pdfIn PDF document text
    • https://autotronics.vn/userfiles/file/vosupanunimisabamixoku.pdfIn PDF document text
    • http://tgtech-auto.com/userfiles/file/letomeramujixezogedema.pdfIn PDF document text
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607638fee2adf---tagivod.pdfIn PDF document text
    • http://uctodane.cz/UserFiles/File/15303042684.pdfIn PDF document text
    • http://tamlaproject.com/userData/board/file/tasidesoniri.pdfIn PDF document text
    • https://citytrafik.nu/images/file/96076652022.pdfIn PDF document text
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/160877c98ca51a---12082170859.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/nosij.pdfIn PDF document text
    • http://luvnchrlysenglishtoys.com/clients/861429/File/95140378310.pdfIn PDF document text
    • http://pension-erlkoenig.de/img/editor/file/10624081950.pdfIn PDF document text
    • http://arcenevents.nl/site/upload/files/47091926766.pdfIn PDF document text
    • http://amy-tsai.com/images_express/userfiles/files/30666349642.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/d5a51a0087e680e81a05eb4a43344241/60879354426.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d9b1d583a61---61116617578.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c1c0cc85b34---xifejar.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/3304057be93899671314f54c14bf23fd/pedesamoluwomufuwaxabajak.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a463d4daee---palalezilajofovi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=dollar+to+funtPDF 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_off0000c55e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC55E 17500 bytes
SHA-256: 6aaf37950cd41ed4e51c9982ed2129beccf4e5c3c489db8449ad7fa8249eadf1
font_01_sfnt_off0000f34f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF34F 9916 bytes
SHA-256: 1524035de45528b09958c265585e9a0ca9435965ba5b3b7568165cc8366cae25
font_02_sfnt_off0001094f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1094F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1