Malicious PDF — malware analysis report

Static analysis result for SHA-256 c7b67b6b192c7795…

MALICIOUS

PDF

73.7 KB Created: 2021-09-05 04:33:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 7c68b27e37f1ad1caff4a62db8d9242f SHA-1: d93845e0bfe27038c9cc194393ac2298549c59b8 SHA-256: c7b67b6b192c77957d33522bfa3a41f2de4400c9a5a3ae8c3d551ca85990c462
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to compromised CMS upload directories. The ML classifier strongly indicates maliciousness, and the heuristic firings suggest this PDF is part of a link farm designed to redirect users to other malicious documents. No scripts were extracted, but the overall structure and URL distribution are indicative of a malicious redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://thuaphatlaihanoi.net/uploads/files/tixozu.pdf In PDF document text
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607472226618d---83061195092.pdfIn PDF document text
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/8339fsp0tmlflpe21qevicjsik/301141167.pdfIn PDF document text
    • https://foundryindia.org/userfiles/file/mububavujugilimip.pdfIn PDF document text
    • http://www.moyekolodin.com/files/kulanovalilenamura.pdfIn PDF document text
    • http://rrbrentacars.com/files/others/13031515940.pdfIn PDF document text
    • http://phukiendoxe.com/media/ftp/file/lafazatanobujibivifu.pdfIn PDF document text
    • http://sieuthibds.net/images/files/tepurunaxej.pdfIn PDF document text
    • http://boldogelet.hu/media/83593681726.pdfIn PDF document text
    • https://doitsolutions.co/wp-content/plugins/super-forms/uploads/php/files/429c35cd2dd69d6c7b1b6ad7a8443acd/40787183460.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/a6d960f4cda70a34e358d5edb9352e4d/gojijox.pdfIn PDF document text
    • https://ht-cooling-j3t.com/contents//files/podalazil.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16118da1a1fc51---97429873079.pdfIn PDF document text
    • https://jollytime.ru/wp-content/plugins/super-forms/uploads/php/files/b21a027cd01adc6e8393d00ca235378b/tarozuzolalaxasilu.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/d4upnjo538951srdfnf379blk0/dobejuzotafigej.pdfIn PDF document text
    • http://dzbnf.com/upload/file///nitemawokatabirulezelito.pdfIn PDF document text
    • https://www.nestroots.com/wp-content/plugins/super-forms/uploads/php/files/vd4qapr1g0ikmp799luj42gkt6/49739629247.pdfIn PDF document text
    • https://masterpieces-mallorca.com/wp-content/plugins/super-forms/uploads/php/files/29a74a692761508be84504de7d38097a/warevamemebetinoxukozowes.pdfIn PDF document text
    • https://greyquotient.com/wp-content/plugins/super-forms/uploads/php/files/fd2ad84e5d0d14b01e45c91e5e692211/sepavut.pdfIn PDF document text
    • http://www.heksan.com.pl/file/notiwip.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c57fea4ec4---kebitunusufiwunavowas.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=suzuki+splash+2010+manual+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_off0000bbd8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBD8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d3ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3EA 17500 bytes
SHA-256: 448c625b02536588d7347a2f86fa1eb568ef08345c45b4da88c51f016bac8053
font_02_sfnt_off000100b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100B6 10932 bytes
SHA-256: 5ad613154f93fdd4274da27af8cc09589de0b73eb6d2886664fe2bcdf0ec15e6