Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4c42785ec507ae4…

MALICIOUS

PDF

75.3 KB Created: 2021-09-15 01:24:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: b813e1380241a95c793db3d36a0f447e SHA-1: 69facaa3fd02c42e824340b8696b4896ae766281 SHA-256: f4c42785ec507ae4f67b8fb6f241c8872c031c983600e6dde66320d3a60bedd4
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as a malicious PDF by ClamAV and an ML classifier. It contains embedded JavaScript, which is often used to exploit vulnerabilities or redirect users. The PDF also functions as a link farm, pointing to multiple external URLs, some of which are hosted on compromised WordPress sites or disposable domains, suggesting an attempt to distribute malicious content or conduct phishing. The presence of embedded JavaScript indicates an intent to execute code upon opening the document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://nedimgame.net/calisma2/files/uploads/70815251753.pdf In PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613c7c318a17c---bopuwitisawat.pdfIn PDF document text
    • http://antwerp-reefer-tournament.be/argt/files/78332032909.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/tugepapipevi.pdfIn PDF document text
    • http://swaminarayangm.org/userfiles/file/90810954795.pdfIn PDF document text
    • https://eijo.in/ckfinder/userfiles/files/ruzogulikivetexapog.pdfIn PDF document text
    • http://eyela.kr/uploadfile/fckeditor/file/lufigasu.pdfIn PDF document text
    • https://www.psk.com.au/application/third_party/ckfinder/userfiles/files/jizobuxeponinomonojejiwem.pdfIn PDF document text
    • http://elverum-revmatiker.no/images/file/47426048629.pdfIn PDF document text
    • https://zagi.hr/files/vowexorasadewu.pdfIn PDF document text
    • http://www.dagmarsvendova.cz/admin/js/ckfinder/userfiles/files/44297874835.pdfIn PDF document text
    • http://105chers.netsociality.com/upload/files/kirokugaweg.pdfIn PDF document text
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/f7f3d422cce85d9d965bd2f1f4b02779/26801345080.pdfIn PDF document text
    • https://prawobrzeze.info/userfiles/file/62546344743.pdfIn PDF document text
    • https://o-dance.com/upload/files/63991984558.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141102a73452---68870514095.pdfIn PDF document text
    • http://ned.ru/uploads/files/kelubodaf.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613113d1a2b7c---79133144895.pdfIn PDF document text
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/922hadpvg52mmcpkq482sp5ikb/xadodef.pdfIn PDF document text
    • https://howardsteeves.com/wp-content/plugins/super-forms/uploads/php/files/98f3276719a640ac48b7cc612e4452be/33269003548.pdfIn PDF document text
    • https://acconpriti.com/ckfinder/userfiles/files/79335897496.pdfIn PDF document text
    • https://dubaimotorcycletours.dubaimotorhomerentals.com/uploaded_images/files/43840020550.pdfIn PDF document text
    • http://biomax.shop/filespath/files/20210909162408.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=gameboy+color+roms+pokemonPDF link annotation
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/090e340d921ef2da6c85a036c2a55adb/valusepesijelolu.pdfIn PDF document text
    • 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_off0000c172.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC172 10732 bytes
SHA-256: c10d6d3d269284f5c708a3e020e569ff799d10cbf0e13fb2422660a0e88189e3
font_01_sfnt_off0000d9f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9F3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f205.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF205 17288 bytes
SHA-256: 8c1c3164f8f86892228b8d51abb509bb8a3779b49286cf5fa2ee70427b312546