Malicious PDF — malware analysis report

Static analysis result for SHA-256 3109baf7d8d085cb…

MALICIOUS

PDF

86.4 KB Created: 2021-08-21 17:53:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 7a7ff42da7ddf989b61ec4f9b1e761c9 SHA-1: e93e2e9c38c5b3f2c1b5d1c1ddf1320c72cb0f2f SHA-256: 3109baf7d8d085cb0aaa2d353ce574a2c1aecdd7b0e50995d7607854964534cf
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content or phishing pages. The document body is heavily obfuscated and unreadable, providing no direct clues to its intent beyond what the heuristics indicate.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nomylo.ru/uplcv?utm_term=how+to+fill+a+bobbin+on+a+brother+vx-1120 PDF link annotation
    • http://dok-vo.ru/userfiles/file/8315819778.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/bjm4tuk6alfv6dtcp2bvcilo60/redataxevexojatumadan.pdfIn PDF document text
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/cc6ceb04659a995bc1ec051bb7356a72/25864750459.pdfIn PDF document text
    • http://alkanboya.com/files/file///17914325168.pdfIn PDF document text
    • https://ols.lighting/wp-content/plugins/super-forms/uploads/php/files/c4b61ad8703d1dbf3ca8e9e9593ae97b/16809878979.pdfIn PDF document text
    • http://saopauloairporttransfers.com/ckfinder/userfiles/files/31139931314.pdfIn PDF document text
    • https://almuhja.ps/ckfinder/userfiles/files/48102877366.pdfIn PDF document text
    • https://aspirans.com/files/file/95424708000.pdfIn PDF document text
    • https://snoman.mb.ca/ckfinder/userfiles/files/basemizefinur.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607cc55134bcd---71279226085.pdfIn PDF document text
    • http://poltinik.ru/userfiles/file/vojexuwupipumupixati.pdfIn PDF document text
    • https://sharidendesignasphalt.com/wp-content/plugins/super-forms/uploads/php/files/587e580265f0d245afc871dbecb9cbc7/mewegu.pdfIn PDF document text
    • http://ventilatoryzlin.cz/images/file/kefom.pdfIn PDF document text
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aaaff762f1f---vebodefekexojapofela.pdfIn PDF document text
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a35aed443b7---34337771491.pdfIn PDF document text
    • https://brune-schmuckwerk.de/ckfinder/userfiles/files/11768411237.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d6931db6f2---30504968059.pdfIn PDF document text
    • http://eyela.kr/uploadfile/fckeditor/file/tijos.pdfIn PDF document text
    • http://bbfrontedelmare.com/userfiles/files/66392527292.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c55b69488e1---63730455724.pdfIn PDF document text
    • http://xn--4k0b43gkwo4gn.com/upload/editor/file/bowuwebeli.pdfIn PDF document text
    • https://tamtam.com.ua/wp-content/plugins/super-forms/uploads/php/files/726985b5f94d30fb11e0a961c18bb851/nulegizenomuragugakunub.pdfIn PDF document text
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/15eb21b2c1fa1cf4e85df0ee462e0e82/gijomubukanidofifogof.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_off0000e8ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8EF 10856 bytes
SHA-256: 896f8b27bc18aa202c2fa37c40a7718ac37b905b7ccfd67203181717cf3f8a9f
font_01_sfnt_off00010209.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10209 18996 bytes
SHA-256: 1cc51e9a0e852de4dcef16f877af58428f634a36d2724f3b587de0c8f060b31a
font_02_sfnt_off00013415.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13415 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1