Malicious PDF — malware analysis report

Static analysis result for SHA-256 239ab705ffb761d8…

MALICIOUS

PDF

82.9 KB Created: 2021-09-15 21:34:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 1fa7dd93dde398c0a0b1114fe80de775 SHA-1: 74bc1546146485fa1db18e833bbe9859cb1656bb SHA-256: 239ab705ffb761d89b48952926af4688012750058c0b13a6caf7f302c200274c
96 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting. The ML classifier strongly indicated maliciousness, and the heuristic firings suggest this is a link farm designed to redirect users. The primary purpose appears to be to lead users to external, potentially malicious, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 https://isuzuphonoi.com/data/dulieu/files/39478463929.pdf In PDF document text
    • http://ovartec.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131511ce2329---mubosixanusibeliwujiwane.pdfIn PDF document text
    • http://mgtuae.com/uploads/file/bavijagojupovivavizo.pdfIn PDF document text
    • https://eseninternational.com/uploads/files/jijawa.pdfIn PDF document text
    • https://www.vasutaszeneiskola.hu/ckfinder/userfiles/files/78282903741.pdfIn PDF document text
    • http://cold.lt/userfiles/file/mozogizov.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/minexinogimenovaterafe.pdfIn PDF document text
    • http://tongchangkj.com/uploadfile/file///2021091400445315.pdfIn PDF document text
    • http://prtourusa.com/FileData/ckfinder/files/20210911_804A84248E90CF4B.pdfIn PDF document text
    • https://speakingparrot.com/upload/ckfinder/files/93786309139.pdfIn PDF document text
    • http://vnationwide.com/userfiles/files/jevukulinosasonopolaja.pdfIn PDF document text
    • https://ktmcollege.org/public_html/userfiles/file/19852052918.pdfIn PDF document text
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/17c0de90c6bf776526da3deba0690fb4/weraj.pdfIn PDF document text
    • http://pincailight.com/zk/UploadFile/file/2021090821371473499.pdfIn PDF document text
    • https://terracell.info/images/file/909857561.pdfIn PDF document text
    • https://valgott.com/images/userfiles/file/86275413802.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fedb5ad80f---95564536210.pdfIn PDF document text
    • https://prtl.pl/userfiles/file/74242912184.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/161410e7a56c42---51031786279.pdfIn PDF document text
    • http://twsl.mingann.info/upload/ckfinder_temp/files/20210909052103.pdfIn PDF document text
    • http://drentmedischadvies.nl/uploads/files/77310406172.pdfIn PDF document text
    • http://ferrocom-spb.ru/userfiles/files/fesamajedosap.pdfIn PDF document text
    • https://mebelihome.ru/upload_picture/nepopixe.pdfIn PDF document text
    • http://nissanotogovap.net/uploads/images/files/88717187189.pdfIn PDF document text
    • https://stiff.pl/ckfinder/userfiles/files/73635599401.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=stream+free+movies+android+phonePDF 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_off0000e1d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1D3 10856 bytes
SHA-256: 7b52ddad4b8183ddfdf73e76aa0e596f08486b87ccb85a3f9563ef759fb919ae
font_01_sfnt_off0000faba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFABA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000112cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112CC 16732 bytes
SHA-256: c4dbf343f782c6abca2e3cbb71cef20e1130010148fde62e1cea975492cdfa65