Malicious PDF — malware analysis report

Static analysis result for SHA-256 e011cd480847db80…

MALICIOUS

PDF

80.1 KB Created: 2021-09-08 11:48:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 42907cc983ae5793d7d716216165fd76 SHA-1: 6dee8f488596816d373d31a590668b6ceae7cc45 SHA-256: e011cd480847db80295ba0206c2e0dc6f73b4aac7deedc87953ba329d60110cf
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a link farm pointing to numerous other PDF files hosted on compromised websites. Heuristics indicate these are likely part of an SEO manipulation scheme or a distribution vector for further malicious content. The ML classifier strongly supports the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://aawyx.com/sites/default/imageuser/file/jedofoxaguxupifonugula.pdf In PDF document text
    • https://www.napariverinn.com/wp-content/plugins/super-forms/uploads/php/files/8bc64696475d2b78ec2e667c2d264fe4/51297223641.pdfIn PDF document text
    • http://gmei.lt/ckfinder/userfiles/files/guremigodufidolava.pdfIn PDF document text
    • http://lovelyspa.net/ckfinder/userfiles/files/86701594195.pdfIn PDF document text
    • http://marta-galan.com/files/varios/file/gagutediz.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160756b497d9ba---55666280224.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/84256914141.pdfIn PDF document text
    • http://artgraf24.pl/userfiles/file/49279112707.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/b99e95e25d7dd5a73f135aafe66d54f7/83829611165.pdfIn PDF document text
    • https://www.olympusnorge.no/wp-content/plugins/super-forms/uploads/php/files/h23medlqcvdah4jaqmcm217vii/xuwiligo.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608304ea3d491---radanegorokesinaranowejem.pdfIn PDF document text
    • http://perksys.com/userfiles/file/68974674058.pdfIn PDF document text
    • https://tecnicadovolante.com/images/file/44504965760.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609611dc64f6c---fadewumumoxirel.pdfIn PDF document text
    • https://vandolderskb.com/images/usr/goxuloxuwe.pdfIn PDF document text
    • http://slsnn.ru/content/files/46410250523.pdfIn PDF document text
    • http://seigyobannkaigaikikaku.com/ckfinder/userfiles/files/74732206492.pdfIn PDF document text
    • http://gojjang.com/uploads/files/7662001884.pdfIn PDF document text
    • http://pokewaveanaheim.com/uploads/files/33950069666.pdfIn PDF document text
    • https://aspaeng.com/files/image/files/dogudeduleluropusowuro.pdfIn PDF document text
    • http://clinicacomciencia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609ad4dbdd0d2---gurivon.pdfIn PDF document text
    • https://bisnismedsos.com/userfiles/file/xafabigaxuleposifosereted.pdfIn PDF document text
    • http://gorisum.net/fckeditor/upload_file/file/kegagupoder.pdfIn PDF document text
    • http://www.advokat.com/app/webroot/img/fck/file/22080182964.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=area+and+perimeter+word+problems+worksheet+5th+gradePDF 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_off0000d510.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD510 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ed27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED27 11272 bytes
SHA-256: 1ef95efb94c453ce89d4badc324a41ed42a8dd54964125bf7e8ce69d1806d323
font_02_sfnt_off00010707.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10707 16756 bytes
SHA-256: ee57204d5960b46f6c6d0992776efc1e028569fba65194c4e356eecc8ca694d9