Malicious PDF — malware analysis report

Static analysis result for SHA-256 c84e16b4220405c7…

MALICIOUS

PDF

75.0 KB Created: 2021-08-31 15:52:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-17
MD5: 9cabf8081160824ca7925387c6bdefe6 SHA-1: 98f80d1bb20a6ee3a5ebd56e8ccfc8153e29babb SHA-256: c84e16b4220405c796b8cf8adc3fa9a7ee040d24a167e793b419fb1e4589d06a
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised WordPress sites. The ML classifier also flagged this PDF as malicious with high confidence. The document appears to be a link farm designed to redirect users to potentially malicious content hosted on these compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://huntic.ru/uplcv?utm_term=2020+itemized+deductions PDF link annotation
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ad9ba4f23b6---vitizej.pdfIn PDF document text
    • http://studiotecnicofrisoli.com/userfiles/files/5623065614.pdfIn PDF document text
    • https://staffxrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/dcd0f53724da99f511f11bb2b9bdc24a/33615863244.pdfIn PDF document text
    • https://cryptoshift.be/anaeter_capital/siteadmin/userfiles/files/28413237729.pdfIn PDF document text
    • https://southernlightingsource.com/wp-content/plugins/super-forms/uploads/php/files/6c6b0d0f538b79f5ed032378263497cb/rajagutoj.pdfIn PDF document text
    • http://sbnjl.com/userfiles/files/16094238213.pdfIn PDF document text
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/ede4afee48f4d55216cf87142aa7b782/21442417929.pdfIn PDF document text
    • https://goodmix-psc.com/userfiles/files/nasowasukizexesoni.pdfIn PDF document text
    • https://anpheatingandac.com/nbloom/fckuploads/file/fedizafarok.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1f173d11a---17353420565.pdfIn PDF document text
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/qua3nfljje695v8h0v4tl90aa1/zebejasi.pdfIn PDF document text
    • https://www.clinicaepilepsia.cl/ckfinder/userfiles/files/9588961209.pdfIn PDF document text
    • http://vonschickenconcord.com/uploads/files/sezalom.pdfIn PDF document text
    • http://tantex.org/tantex/tantexuserfiles/file/dupuxugekerodatim.pdfIn PDF document text
    • http://jun-travel.com/userfiles/file/pafanebajajemufikugejuna.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160b8f86d15868---41902371425.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160815e5a8e8a9---84953698111.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/vuzifafepewo.pdfIn PDF document text
    • https://advik.net/userfiles/file/75964912082.pdfIn PDF document text
    • http://tms-technology.com/ckfinder/userfiles/files/zirorajilifelaloz.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609e65c1d04b5---xazirisimak.pdfIn PDF document text
    • https://ivanda-commerce.hr/userfiles/file/42129630413.pdfIn PDF document text
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc5c002de4---63559039352.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/80e8b0c471baf34ea14b28fea88d00b7/kuxet.pdfIn PDF document text
    • 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_off0000c35d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC35D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000db74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB74 10528 bytes
SHA-256: d9ad2e1c1bf3584ee5d5942517900e9f1af983b252ceabef51df8cebd4479a0b
font_02_sfnt_off0000f37f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF37F 16728 bytes
SHA-256: fa30c655c88ab5349063ac62c7ab5acf28ad5849aa819cd5758ec849c84ace86