Malicious PDF — malware analysis report

Static analysis result for SHA-256 40c14e8981ba579a…

MALICIOUS

PDF

69.7 KB Created: 2021-09-08 16:13:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: c59abfdffd2c68963f2a2e5e7aadc436 SHA-1: 4b8ffab53d98cfd9856c23cb9aa46cf4a96094ec SHA-256: 40c14e8981ba579a60a123dafe30945c4bb1e45f50def8dc23c7d5bffd9a0bc0
96 Risk Score

Malware Insights

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

This PDF file contains a link farm, a common technique used to redirect users to potentially malicious websites. Several heuristics indicate that the PDF is designed to host a large number of links, many of which point to compromised or disposable hosting. The ML classifier strongly flagged this PDF as malicious, supporting the assessment that it is part of a malicious campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

Heuristics 5

  • 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://tjchenxing.com/filespath/files/20210902041219.pdf In PDF document text
    • https://cyberbirddog.com/userfiles/files/64594467747.pdfIn PDF document text
    • http://theprofitnesstrainers.com/userfiles/file/6868501928.pdfIn PDF document text
    • http://rajskiewakacje.pl/userfiles/file/91645538627.pdfIn PDF document text
    • http://cuboni.com/uploadfile/hong202109041905058226.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612fc57be6e2d---jawawujewufobekaside.pdfIn PDF document text
    • http://bodemveenweiden.nl/bodem-veenweiden-img/fimisazunajerigi.pdfIn PDF document text
    • http://gearonlaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/72145331247.pdfIn PDF document text
    • https://santa.my/images/users/00000000/files/rokomugigerivubolokaf.pdfIn PDF document text
    • http://danangsculpture.com/uploads/image/files/tosupejimagozovetujasup.pdfIn PDF document text
    • https://12tiga.com/contents/files/95122489185.pdfIn PDF document text
    • http://schoonhovensvrouwenkoor.nl/ckfinder/userfiles/files/likafebi.pdfIn PDF document text
    • https://afra24.com/basefile/afra24/files/besezovutal.pdfIn PDF document text
    • https://www.karavanlakesfet.com/wp-content/plugins/super-forms/uploads/php/files/21f206b76675c7052b60e53ac6fb32e1/75173450498.pdfIn PDF document text
    • https://drivetripper.com/userfiles2020/files/jabovaduvakakalanija.pdfIn PDF document text
    • https://testgit.begurholidays.com/uploads/userfiles/files/wilegesotemifokebunet.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613404e0e109d---97910319430.pdfIn PDF document text
    • http://iweldbot.com/ckfinder/pho/files/rololizevafe.pdfIn PDF document text
    • http://xdata.pl/app/webroot/img/ckf/files/mujagu.pdfIn PDF document text
    • http://euroteam.vn/ckfinder/userfiles/files/zokefegatana.pdfIn PDF document text
    • https://blokhol.com/upload/files/tesol.pdfIn PDF document text
    • https://yourtuscanyguide.com/wp-content/plugins/super-forms/uploads/php/files/ohjl1vhoppnh7qchdhbnnt3i91/98590455352.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/161338e7667a74---51334270635.pdfIn PDF document text
    • http://ladyvenus.it/userfiles/files/5115927172.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1612ec6d301524---41040230239.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=family+and+marital+counseling+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_off0000b2fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2FB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cb12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB12 11156 bytes
SHA-256: da8f4267bfce2f5794f4345c2a1a799a0ca10d81774ef8f4ac5cadffc74618b1
font_02_sfnt_off0000e4ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4EA 14628 bytes
SHA-256: b259f647ed08abb28055331d8c97911a8f74f2aaac3b85cd4db08f6cf6925a37