Malicious PDF — malware analysis report

Static analysis result for SHA-256 a324cb56fd2a9225…

MALICIOUS

PDF

79.4 KB Created: 2021-09-15 09:49:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 3e24e28a0c5cb45fefe56365fc4bf530 SHA-1: 9564ca671549dea9e771a6eb87170115ffa8eb72 SHA-256: a324cb56fd2a9225e23faf11713ba61773ca8964285dae0cb12953782704f619
156 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous URLs pointing to various websites, many of which appear to be compromised CMS uploads or hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The primary attack pattern observed is the use of a link farm to redirect users, potentially leading to further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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://szalkasszorutacskok.hu/app/webroot/files/content/files/75231630775.pdf In PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613595d5cb7a8---bedekikinapawe.pdfIn PDF document text
    • http://foxhill101.com/userimages/levesovawasad.pdfIn PDF document text
    • https://feldmann.pl/userfiles/file/92434125944.pdfIn PDF document text
    • https://www.ogblfrontaliers.fr/wp-content/plugins/super-forms/uploads/php/files/p3p2mbsg1af9aj4ef2jilgljl6/37647094096.pdfIn PDF document text
    • http://www.valathors.com/ckfinder/userfiles/files/63932449497.pdfIn PDF document text
    • http://orem.mn/uploads/files/midinamam.pdfIn PDF document text
    • http://indyskischool.com/ckfinder/userfiles/files/wojap.pdfIn PDF document text
    • http://carbontuning.ru/file/74879541119.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/203a40642405066e6126eef9ad6c5fde/23121942496.pdfIn PDF document text
    • https://cabsfromheathrow.com/userfiles/file/kekotiveguvek.pdfIn PDF document text
    • http://nikolalepojevic5.com/multimedia/file/pifivuzadivux.pdfIn PDF document text
    • https://iskoruma.com/upload/ckfinder/files/gelodivo.pdfIn PDF document text
    • http://novehorizonty.sk/userfiles/file/pozemotipamedenusuru.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/1c019de54a671cb36e805b697f670142/kimotufeledupaba.pdfIn PDF document text
    • http://groupkaishan.com/d/files/bowelipe.pdfIn PDF document text
    • https://nbc.com.vn/ckfinder/userfiles/files/letavisojujofilesi.pdfIn PDF document text
    • http://acelybio.com/upload/files/85605819903.pdfIn PDF document text
    • http://ufcnagykanizsa.hu/userfiles/file/pebasizisurovalugitor.pdfIn PDF document text
    • http://lnhaihui.com/userfiles/file/20210906172212_1379675976.pdfIn PDF document text
    • http://www.liveartsaskatchewan.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f7b3686ca3---95958299999.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1613ec36caa409---2826188644.pdfIn PDF document text
    • http://karthikeyanjayaram.com/userfiles/file/dikixer.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=java+games+download+apkPDF 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_off0000d10f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD10F 18256 bytes
SHA-256: 42feffb79e97d627155e37f49a0d411cf337001999c030215599661bf3638fb0
font_01_sfnt_off0000ffee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFEE 10680 bytes
SHA-256: d7538ce0b5c15b78835a984c60e28b1a7f4c1f46df94b6e959584f04dc5d690b
font_02_sfnt_off0001184b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1184B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1