Malicious PDF — malware analysis report

Static analysis result for SHA-256 a55b7ee06f7399bf…

MALICIOUS

PDF

76.0 KB Created: 2021-09-17 16:16:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: bc403c4bb44f50386a34ece1e4b72f5e SHA-1: 05c8a6df1aaf03db4adff896076dbd02ff57a64f SHA-256: a55b7ee06f7399bf1277a71e4a06d9c5b34c0efece3ba44a2e87003de1c4340e
164 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and numerous external URIs, many of which are part of a link farm hosted on disposable or compromised domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or to download further payloads. The embedded JavaScript is a common technique for initiating malicious actions within PDF documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://drafthe.ru/uplcv?utm_term=best+phrasal+verbs+book+pdf PDF link annotation
    • https://gastriklandsbf.se/UserFiles/files/17611094858.pdfIn PDF document text
    • https://coebmsf.com/userfiles/file/90048128210.pdfIn PDF document text
    • http://scpt.it/userfiles/files/gugitonafabiniwuxawe.pdfIn PDF document text
    • http://cityfate.com/files/files/71886125690.pdfIn PDF document text
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16138c557835c3---lexir.pdfIn PDF document text
    • http://konditsionery-zheleznodorozhnyi.ru/upload_picture/file/33841174983.pdfIn PDF document text
    • http://sibaco.ru/ckfinder/userfiles/files/magop.pdfIn PDF document text
    • https://habibitours.org/ckfinder/userfiles/files/23163027143.pdfIn PDF document text
    • http://hoaisonland.vn/upload/files/wawumerom.pdfIn PDF document text
    • http://ztkammer.at/uploads/file/15000906375.pdfIn PDF document text
    • https://baobiachau.com/luutru/files/zudowavoxutozisajer.pdfIn PDF document text
    • http://ministerium.pt/files/30207678310.pdfIn PDF document text
    • http://ranjitabiswas.com/userfiles/files/waxupi.pdfIn PDF document text
    • http://leeharringtonhomes.com/userfiles/file/pofefejemutalar.pdfIn PDF document text
    • https://kingcarmotorista.net/uploads/files/vewanesatuvakuxudojo.pdfIn PDF document text
    • http://branonperformance.com/ckfinder/userfiles/files/95396029190.pdfIn PDF document text
    • https://ausztriasi.spawellness.hu/upload/hirlevel/files/628536584.pdfIn PDF document text
    • http://dade666.com/userfiles/202109file/2021090206031670554.pdfIn PDF document text
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613167bebc894---45471472790.pdfIn PDF document text
    • http://duetsepolno.pl/userfiles/file/32437919591.pdfIn PDF document text
    • http://www.dagmarsvendova.cz/admin/js/ckfinder/userfiles/files/kusaxutekuwalarimevit.pdfIn PDF document text
    • https://wonwon.taipei/photo/file/28639508037.pdfIn PDF document text
    • https://mimpiindah168.com/contents/files/bunekuw.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/e736ac0dc30bf5590ce47fdd87943f98/10731689340.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_off0000c509.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC509 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD1B 17116 bytes
SHA-256: 11c38e0094adc493a4915bd36763d95cb8d6c0d19012562c0144034b7d473d59
font_02_sfnt_off0001099d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1099D 10748 bytes
SHA-256: ef33b823b2718e615fa2904e2118c2126ed20437b7b004f1c3def041dfd00a19