Malicious PDF — malware analysis report

Static analysis result for SHA-256 21e05aa5b870db7e…

MALICIOUS

PDF

81.5 KB Created: 2021-07-07 15:49:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: da8f5912bb09211164fbdbb6402bed89 SHA-1: e6e60091647dd31cadc0f495fe9dcee6b0df5c4d SHA-256: 21e05aa5b870db7ebafc0a6ef4cd25e0fd4fcf0c17abf086cfb2244b3754f405
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous compromised websites, many of which host other PDF files. This suggests the document is designed to lead users to malicious content, potentially for phishing or malware distribution. The ML classifier strongly indicated maliciousness, and the structure aligns with techniques used to obscure malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160e4b3c088f8d---wujaj.pdf In PDF document text
    • http://grandinhr.eu/images/user/file/90145931242.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/f5rcb9cdcq72k10t1ifo9pbq6q/dujezebasakegiduduwusa.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/1609425763b57c---10584622980.pdfIn PDF document text
    • https://www.onestopnaturalstore.ca/wp-content/plugins/super-forms/uploads/php/files/09eimptv7eap9vi7rcbi18tpmu/rukufurokerenesik.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c536e74d4ad---zugagaripajezedefir.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bf7e70e3732---16098227277.pdfIn PDF document text
    • https://eghamatyab.com/basefile/bainbookcom/files/79614398690.pdfIn PDF document text
    • https://skazkavdom.com/wp-content/plugins/super-forms/uploads/php/files/6feaa347ea8778e96c3363818ed7ef61/71789591256.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/ade9e8bee704cbdff1b9c3407df60106/nifewexusarujosutiwepa.pdfIn PDF document text
    • http://eltonltd.ru/sites/default/files/uploads/13384575389.pdfIn PDF document text
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2a0be1a9d2---diputokig.pdfIn PDF document text
    • https://smilepath.com.au/wp-content/plugins/super-forms/uploads/php/files/fb389091ad3855ebcf5c01142d70e9cf/89823388717.pdfIn PDF document text
    • http://brightwayconsultancyservices.com/userfiles/file/70647314499.pdfIn PDF document text
    • https://mimpishiodua.com/contents//files/tewitodejasakozeki.pdfIn PDF document text
    • http://vhshf.de/File/28210256021.pdfIn PDF document text
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a299a5bb66---gikefos.pdfIn PDF document text
    • http://manavpublicschool.org/manav/userfiles/file/25499786504.pdfIn PDF document text
    • https://www.lightingsolutionsinc.net/wp-content/plugins/super-forms/uploads/php/files/d9c44f3c4d5f4e0f19bbbd00c68a5420/darivunugomitufibiroj.pdfIn PDF document text
    • http://tcurryproperties.com/konadnew/userfiles/file/81438939127.pdfIn PDF document text
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/2bb7044bbe4bdb265f5476c690df8895/30108388440.pdfIn PDF document text
    • http://n2nlah.org/UserFiles/file/birur.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=4+words+answers+level+2PDF 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_off0000db9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB9E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f3b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3B5 10304 bytes
SHA-256: 7714cb2224f0686192f87d5d722a45d4f1d7bcd42f12ad966402ce7513559df7
font_02_sfnt_off00010b26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B26 17076 bytes
SHA-256: 1e47c68f50e7069bb3245bc8b0cba4f2f38f7e4259bd1fe078ea2171803d5b47