Malicious PDF — malware analysis report

Static analysis result for SHA-256 e3f6f93857a46c0e…

MALICIOUS

PDF

76.8 KB Created: 2021-09-06 00:47:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 1b73c3072277e8bd9204774c5821c2ff SHA-1: 9189d5805d1738053437b9626830e270ab3952fa SHA-256: e3f6f93857a46c0e2635ba2a84bb107862a2d05ad2cbc8fc90136982e44e5b83
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm used for SEO manipulation or to distribute further payloads. The presence of these links and the overall structure align with phishing or malicious redirection tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9901

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 https://empresa-venta.hr/files/1199683531.pdf In PDF document text
    • http://lorichphoto.com/pictures/file/36431520568.pdfIn PDF document text
    • https://rtvpuls.com/ckfinder/userfiles/files/xolodavibujupugiruvufove.pdfIn PDF document text
    • https://soft-print.pl/app/webroot/media/files/motewira.pdfIn PDF document text
    • https://baodinhsolar.com/wp-content/plugins/super-forms/uploads/php/files/r116fmnv45f6fkc2aspgn6c7tk/67355452880.pdfIn PDF document text
    • https://baohohoanglong.com/userfiles/file/10268793108.pdfIn PDF document text
    • http://hydrogears.com/survey/userfiles/files/misoboxegobasew.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160873fcdd8d04---zepeduveriwegudokeruzuse.pdfIn PDF document text
    • https://xn--fct5g39pjpo.tw/upload/leakstop/files/37273427253.pdfIn PDF document text
    • http://archissimo.eu/userfiles/files/robujus.pdfIn PDF document text
    • http://nextgenship.net/upload/file/20210713162619132033.pdfIn PDF document text
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adbffab38ce---lodurosalipox.pdfIn PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/160abb870626d9---labinazalof.pdfIn PDF document text
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/rdqn8u1dds98aa54rme9i0sor0/13145719961.pdfIn PDF document text
    • http://prestizhstroycompany.ru/SITE/files/editor/file/vununoxer.pdfIn PDF document text
    • https://spbmworld.com/anaeter_capital/siteadmin/userfiles/files/39918739725.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/77c5de8dfd09859733472896f9a86bab/zaxewifopigi.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160d2e2a0c4fbf---17788314770.pdfIn PDF document text
    • https://www.charroninc.com/wp-content/plugins/super-forms/uploads/php/files/061172cc9a257ea4b449b3d0cbf6b13d/zurosigedaxokeb.pdfIn PDF document text
    • http://glamour-nsk.ru/ckfinder/userfiles/files/todifixupememajoda.pdfIn PDF document text
    • https://acgroupenterprise.com/userfiles/file/51866070329.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607c18e66cfa6---19853546095.pdfIn PDF document text
    • https://elpollopaulino.com/cenavarra_userfiles/files/5215708268.pdfIn PDF document text
    • http://vonschickenconcord.com/uploads/files/jixabuzab.pdfIn PDF document text
    • https://www.bussmann-tiefbau.de/ckfinder/userfiles/files/ronalolaposararune.pdfIn PDF document text
    • https://adepotcustom.com/UploadFiles/file/20210502225604174.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/160701605d51f7---78786032197.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=free+worksheets+for+teachers+social+studiesPDF 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_off0000c854.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC854 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e06b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE06B 10724 bytes
SHA-256: 19bb23ecc5a91b127050ed8ea0e728138ad857ad36c1999c6bf466e62f15eefd
font_02_sfnt_off0000f942.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF942 16956 bytes
SHA-256: 4f7009f3226d4b687d0c74c5e0c17022e7eb5f32d81d581afe68633960ed0b23