Malicious PDF — malware analysis report

Static analysis result for SHA-256 821048137d674bd6…

MALICIOUS

PDF

88.7 KB Created: 2021-07-19 13:58:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 46090ad3ab53f2656b5a570f1e730ab8 SHA-1: 14a8760bc5545fbb8013830b0ca58ceb580a6ba1 SHA-256: 821048137d674bd68439f01e1adc3963acab2cde9afc87f565811adede66c9b0
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous external URLs, many pointing to compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, but the structure suggests an attempt to lure users to external, potentially malicious, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://eurotechcorp.vn/admin/webroot/upload/image/files/solikawewef.pdf In PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/990u9l30sgh7dpufsajgeg8r36/fudajo.pdfIn PDF document text
    • https://drisraadentalcenter.com/userfiles/file/70729739675.pdfIn PDF document text
    • http://english-life.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606f981f4e017---92498277091.pdfIn PDF document text
    • http://industrialdevices.in/uploads/8444964800.pdfIn PDF document text
    • http://kondicionery-krasnogorsk.ru/upload_picture/file/fufotodipipidi.pdfIn PDF document text
    • http://xn--9p4b29dncp2cc6y.net/upload/fckeditor/file/lonogosogureselomonobuxe.pdfIn PDF document text
    • https://xn--80aaaglcftt5alesfkk7f.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/1b2ccaa4610d26d6bcb0ab3aa14e8b90/13862886552.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/on7b673un6miesigt96dd3nt3h/48213351858.pdfIn PDF document text
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/db9222dfc55d623a3ab7a21ccc18a3f0/sitebagirotidage.pdfIn PDF document text
    • http://nuraski.pl/wsg/userfiles/80669860210.pdfIn PDF document text
    • https://expeditions-travel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f86c01c960---fojepafajitokiraso.pdfIn PDF document text
    • http://tryinvest.eu/userfiles/files/nesutavatu.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608bf4b3ab2cb---jubabegelizuvazaweser.pdfIn PDF document text
    • https://remoteworkerclub.com/wp-content/plugins/super-forms/uploads/php/files/4a426d2055dc006a00fd377d84c43a52/95175330492.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160856f409eaa5---diwojenabijesatavowudul.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d00c033c43---pojuvexexobebudi.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a635a690f0---78252853613.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160caae3411c07---befagiwogabagazepevu.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160c5a65dd84db---zezuxo.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/160c25901872bc---gufimasirubo.pdfIn PDF document text
    • http://mu-rrrc.com/userfiles/file/28273055104.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c867f400bb---wofokosojovejegaza.pdfIn PDF document text
    • https://irisapp.cn/uploadfiles/fckeditor/20210710/file/16258650596843.pdfIn PDF document text
    • https://benchmarktransitions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a73fc2b800e---tupolonidaduwumagurop.pdfIn PDF document text
    • https://bluebeakbranding.com/wp-content/plugins/super-forms/uploads/php/files/72f3f2784c8cded6c06aaa7574256595/35811010115.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=the+medical+model+definitionPDF 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_off0000fa6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA6C 16768 bytes
SHA-256: c406af3f7171e4458f12b327e986cfa54ed661596536e243f2d0486350228751
font_01_sfnt_off000125b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125B3 10436 bytes
SHA-256: 2bf7c7c72db475f3f92e292e229944424552c067a9870f543ac23fd39b9374ca
font_02_sfnt_off00013d22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D22 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1