Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8cb8cdf336c4ffb…

MALICIOUS

PDF

91.4 KB Created: 2021-06-25 15:12:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2026-06-05
MD5: 257aa8e8860af31c225e6fee90a43796 SHA-1: 0e978b595453179d7b310bcee0828f2ee1c2e4fa SHA-256: a8cb8cdf336c4ffbe7949fc0b471bfaa48566742e861816c8afdbd14e1c65f13
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, with numerous embedded URLs pointing to various websites, some of which are hosted on compromised CMS upload directories. The primary attack pattern involves luring users to click on these links, potentially leading to further compromise or phishing attempts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://rauvuonsach.com/images/uploads/files/vavipuxovunu.pdf In PDF document text
    • http://teplospectr.ru/images/files/26114757381.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/7nv9i5qdd3jjcidbqlm8ip54o9/pafonuzijegiruwalim.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/88lt2eucbov6aohom9effg129f/kumozo.pdfIn PDF document text
    • https://ksuskalology.com/images/file/faladozibowugedujene.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160886837aad96---34443369381.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/50300dc1549f6e4ac09397b0ebe05983/62787561703.pdfIn PDF document text
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/72d90c31ca7eb79d669be77a99c24037/litavomokogapesadonunupe.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/160874cf5e8768---13653006831.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/pixejobepumabakivavu.pdfIn PDF document text
    • https://85097781.com/upload/files/maxuxekopuxepa.pdfIn PDF document text
    • https://shiphangnhanh.net/uploads/image/files/paxepakamovo.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f17c9a0b08---bisovudaxuxi.pdfIn PDF document text
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/1608e7eda670a5---baferulorid.pdfIn PDF document text
    • https://digicpictures.com/downloads/rumonadepuvatowixidorisu.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/bcsucb3lf1amihsqo8cpsahtg7/61361331433.pdfIn PDF document text
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084df1fbe23e---tuwaposuvax.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9078007cc1---64220669746.pdfIn PDF document text
    • http://allprintusa.com/admin/images/file/21176900725.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=day+dreamer+night+thinker+quotesPDF 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_off000103ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103EF 11100 bytes
SHA-256: 9e691350e51d6cc3e52f11d164bf1482a6c5505b88de3eafae0b6b0975a631d6
font_01_sfnt_off00011d1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D1E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013530.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13530 17132 bytes
SHA-256: 0253b88d497e4e429e073f6f220ba052ac68d6e16d182a860d00c0955dad33f4