Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef18648f57ac3a8a…

MALICIOUS

PDF

125.7 KB Created: 2021-07-03 01:00:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e065ada716099f6f620071b99ad41415 SHA-1: 41bba9b9b6ff797e394301736d068edbf2fb151f SHA-256: ef18648f57ac3a8a31eddeb933d6819c5a15f551c641b65c802a207a1ab562a0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics indicate it functions as a link farm, hosting numerous links to other PDF files, likely for SEO manipulation or to distribute further malicious content. While no scripts were explicitly extracted, the PDF structure and embedded links suggest it may leverage JavaScript for malicious actions, such as redirecting users to compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a903b9593f4---88544613560.pdf
    • http://malagi.pl/user-files/fck/file/74143301619.pdf
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b29fc4c3124---rakugus.pdf
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/5resuo0f437gdg1k4tslft9u04/46376616067.pdf
    • https://zionapostolicministries.org/uploads/files/5913451770.pdf
    • https://www.ediliziaindustriale.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc731d7f98b---xubekigixozopa.pdf
    • http://abnicum.com/files/file/49789055510.pdf
    • http://tasteofruraleurope.eu/upload/File/80904846406.pdf
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/160965985ea8c9---36711059430.pdf
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080a459f2dc3---zevimufov.pdf
    • https://mmszke.hu/files/file/67058679483.pdf
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/ac9420ac0a8231eea9cdab7ac53550a9/82990194973.pdf
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079c86020953---71946914053.pdf
    • https://orldoc.ch/wp-content/plugins/super-forms/uploads/php/files/6bb3i6e0jkbpqt6rr3mi4i9r05/833701172.pdf
    • https://www.ideaklinik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5888817bc---zazotipamufe.pdf
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/b687155f24adbbc078dbb16657b3b8c9/7896794491.pdf
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607d985e115f4---narebexikogege.pdf
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/160904c63a38ef---sivamimekabimaf.pdf
    • http://www.zopfitravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ebab5dfdac---sotave.pdf
    • http://chemonova.com/FCKeditor/file/92207455574.pdf
    • https://www.azembay.com/wp-content/plugins/super-forms/uploads/php/files/p72rdeg7djtf3mk82sugii2clh/94155646679.pdf
    • http://stellar-toys.com/ckfinder/userfiles/files/26185744295.pdf
    • http://www.naraihillgolf.com/admin/userfiles/file/44836802109.pdf
    • http://shinies.ru/img/lib/file/kasaxetomon.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=3+blind+mouse
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00018687.bin
07a0f1439c3c085ad2d0021c1f709064245b706cf2b9c8544ce104502ef99cde
pdf-font-stream PDF embedded font (sfnt) at offset 0x18687 10364 bytes
font_01_sfnt_off00019dcc.bin
217538dee649bf0d7e1011766a891283aacdb7ca61a819ae585303eabc722cdf
pdf-font-stream PDF embedded font (sfnt) at offset 0x19DCC 19288 bytes
font_02_sfnt_off0001d183.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1D183 16792 bytes