Malicious PDF — malware analysis report

Static analysis result for SHA-256 5858ae22f113df53…

MALICIOUS

PDF

99.0 KB Created: 2021-07-16 17:25:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 7729b9fdde2b54a6fd4211acb1cdfcee SHA-1: 1fc3a9b0ced45bdf55f4be28352e0217ad1880eb SHA-256: 5858ae22f113df5335f6830f2e59e8487fcfd0bc59380e8295d11dbfbd8a6fc9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by ML classifiers and ClamAV, detecting it as a phishing trojan. Static analysis revealed it functions as a link farm, with numerous embedded URLs pointing to various websites, including those hosted on compromised CMS uploads and disposable domains. This suggests an attempt to lure users to potentially malicious sites, possibly for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9922

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://kurskodkb.ru/page_edit/_samples/userfiles/files/28437691136.pdf In PDF document text
    • http://dgjinhak.kr/DATA/upload/files/202105291210333866.pdfIn PDF document text
    • http://dok-vo.ru/userfiles/file/jinugo.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073f8623da84---67233445918.pdfIn PDF document text
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c385270dccf---xagipivisebot.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bb5f6ab0a6---gofurudiw.pdfIn PDF document text
    • http://dj-venci.com/uploads/pages/files/kevadudexunetubilajup.pdfIn PDF document text
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/69fbe017bb0b45fb68168e5d6980c865/fevebuzaxozesodapugimufam.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/fajj56be2kq72a9n12lgdukf5t/fiserajakalebob.pdfIn PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/34eda945aa84c751deb9cdd942578db1/7270797950.pdfIn PDF document text
    • https://www.straightmyteeth.com/wp-content/plugins/super-forms/uploads/php/files/e1cd81f9cef1a99a77e5ef908a2fbea3/wexofelexabazem.pdfIn PDF document text
    • http://goldenpeak.it/userfiles/files/bogozepaganujotigovi.pdfIn PDF document text
    • https://mediaget.ru/userfiles/files/6918634242.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/o9ise88gqb0rdh5r48f66pv7h5/93336218203.pdfIn PDF document text
    • http://allamericannursing.com/userfiles/file/79542441706.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/12f5f1981b07f6ec6fbb84c34291ca9e/julobatutunedujozejefidip.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/9e8e89e8db40b0596427edf0e4c798bb/28865126139.pdfIn PDF document text
    • http://www.gaviprintpack.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b226ade4f2---54629710297.pdfIn PDF document text
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/u2cq6elvcs5a8k5s9q6tpbvqun/92023731503.pdfIn PDF document text
    • https://lea-inc.com/wp-content/plugins/super-forms/uploads/php/files/863f4b1d91f76c22369d93037eb40520/kigisojarefuxuz.pdfIn PDF document text
    • https://aulacvn.com/upload/fck/file/wurelaramukefejanixujexir.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e7be23ccabf---rizedavaneridarugozuvob.pdfIn PDF document text
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/c60ac14966e0e9597517ed4da8979e20/bamenakupuwovo.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160efe2307fce3---xivorotixabuzom.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160989e447a5c2---sixinakupebuzu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=diverticulitis+diet+during+flare+upPDF 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_off00011ed0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11ED0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000136e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136E2 17304 bytes
SHA-256: 0acfd2a4637a1e93379fddb3efb696151fc3620adb73efc5a822e4b9fdf68749
font_02_sfnt_off0001640c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1640C 10844 bytes
SHA-256: 49566049852ef8c3d283fd8939a3e4d37b89d4aa30aac818eded815ad7135750