Malicious PDF — malware analysis report

Static analysis result for SHA-256 257f83e285ceba65…

MALICIOUS

PDF

89.4 KB Created: 2021-09-08 01:49:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 107f3d12cc90d0966e1b43be1a8ed6a2 SHA-1: 74d0675983d75d5a2e9e8331167ca1c48a252e99 SHA-256: 257f83e285ceba652e7b88cbfbbc1bbd3032781b8a1e395dc4c6fa2e2dbd4aae
156 Risk Score

Malware Insights

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

The PDF was flagged by ML and ClamAV as malicious, with heuristics indicating it functions as a link farm pointing to compromised WordPress sites. The embedded URLs suggest an attempt to lure users to malicious content, likely for phishing or to download further malware. No scripts were extracted, but the structure and URL patterns are consistent with malicious PDF lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8c76bba5c7---41561085933.pdf In PDF document text
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ccb1688f807---jemujenuzonarojizulomu.pdfIn PDF document text
    • https://soosekszer.hu/upload/files/gamesanoxup.pdfIn PDF document text
    • http://cn-polylysine.com/d/files/31320922185.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b0283a70f1---31187861990.pdfIn PDF document text
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/bhts1scur93m36cl4ddab8552h/27697604744.pdfIn PDF document text
    • http://wib24-admin.de/uploads/file/sulirilurenewib.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/429506955.pdfIn PDF document text
    • http://pm-property.pl/userfiles/file/62322151304.pdfIn PDF document text
    • http://tcsm62.org/uploads/news/file/81052338856.pdfIn PDF document text
    • https://typeone.com.my/ckfinder/userfiles/files/fefaramusefe.pdfIn PDF document text
    • https://cebrigantina.com/025-CEB/images-editor/file/numalututemi.pdfIn PDF document text
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/160cde2048c4ec---87959804454.pdfIn PDF document text
    • http://jinyezi.cn/upload/zesufilixinob.pdfIn PDF document text
    • http://biometria.pl/photos_fck/file/43744724044.pdfIn PDF document text
    • https://coopinproject.eu/ckfinder/userfiles/files/wujopirif.pdfIn PDF document text
    • http://lamekatus.ee/uploads/ckeditor/files/39677327483.pdfIn PDF document text
    • https://serini-cloud.pl/uploads/editor/file/31262261341.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/7d730p4hin26qll686b6gh2351/jizujesezojuzufatunile.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/pisugezilizepamowimos.pdfIn PDF document text
    • http://www.gaviprintpack.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1bff21030a---61297966474.pdfIn PDF document text
    • https://homestayhoian.vn/uploads/image/files/73067854875.pdfIn PDF document text
    • http://bhs76reunion.com/clients/e/e7/e717e6e8e39ea4daeda922698d41f3c9/File/sabepupidugudutugiwo.pdfIn PDF document text
    • http://www.atrium-tuiles.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608783749ba40---voxopetenojemepeb.pdfIn PDF document text
    • https://abyway.lv/images/ck_images/files/83062622068.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=ejercicios+equilibrio+termico+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_off0000f0da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0DA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000108ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108EC 21232 bytes
SHA-256: 50fe5dea2f9041889667533b4b538f7b6f489cc68a5af66e13fa5d2b60b274e5
font_02_sfnt_off00013e78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E78 11012 bytes
SHA-256: 15bdd3bb475abdac51edc5ca44162d6db98a0cb6526f18021f295aafb24490b6