Malicious PDF — malware analysis report

Static analysis result for SHA-256 c67826a923fef326…

MALICIOUS

PDF

87.7 KB Created: 2021-09-12 12:47:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: f0537b0d96337382015f75fd733f40bb SHA-1: 45f9e561c85a0464884f8982a36715d3f7187588 SHA-256: c67826a923fef326b8eb1135c32c61f778d29d12d927cd25c17498421cff9df6
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It functions as a link farm, containing numerous embedded URLs that point to various websites, many of which appear to be compromised or disposable hosting. The primary purpose is likely to direct users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://medvor.ru/uplcv?utm_term=wps+hacker+for+android+9 PDF link annotation
    • https://walnutcreekguide.com/wysiwygfiles/file/53639081228.pdfIn PDF document text
    • http://surveycook.com/upload/tmp/202109/file/74106938135.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16137e74b4687f---85214853395.pdfIn PDF document text
    • https://www.mtiwelding.co.uk/admin/ckfinder/userfiles/files/lipafudada.pdfIn PDF document text
    • http://zzzwchem.com/upload/files/kezoviv.pdfIn PDF document text
    • http://mylodge-naoshima.com/images/blog/file/78678752339.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/87802816b33761d92391c14385b23050/4517624180.pdfIn PDF document text
    • https://myhoorayhealth.com/wp-content/plugins/super-forms/uploads/php/files/f6b70fbe59977643a329b0447376425b/65085360222.pdfIn PDF document text
    • https://lifo-sea.com/ckfinder/userfiles/files/malowikizifebapupup.pdfIn PDF document text
    • http://happyland-nsk.net/ckfinder/userfiles/files/52267882315.pdfIn PDF document text
    • https://mimpishio1.com/contents/files/gafemewiwikajob.pdfIn PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dab1dc0977---pisik.pdfIn PDF document text
    • http://hnkingdee.cn/Files/file/2021948460.pdfIn PDF document text
    • http://diversecityuk.com/userfiles/file/xodixomoropimuzonom.pdfIn PDF document text
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/g6471tfcc4a2vl8jd7n7vn28gm/42602225400.pdfIn PDF document text
    • http://www.lbtfilm.com/uploads/files/kojabaramupitisowas.pdfIn PDF document text
    • http://cmtdental.com/upload/ckimg/files/73144650152.pdfIn PDF document text
    • https://crbz.ru/userfiles/file/vinasizojozenutimasiri.pdfIn PDF document text
    • http://zuche0551.com/upload/file/4327384415.pdfIn PDF document text
    • http://zhjpharm.com/upload/files/13834486927.pdfIn PDF document text
    • https://happen.webasl.com/userfiles/file/12901725726.pdfIn PDF document text
    • https://clubslotalmatriche.com/calcas/file/ruwilogit.pdfIn PDF document text
    • http://personal.sut.ac.th/chantira/port/ckfinder/userfiles/files/nokaruruvukexed.pdfIn PDF document text
    • http://ilkjv.com/Images/Media/files/35072291537.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_off0000f050.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF050 18604 bytes
SHA-256: e38a78064aad22c5cea70b724ed4c3c338f28b9ddccd1ba88df1da94a3dac9ac
font_01_sfnt_off0001203a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1203A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013851.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13851 10824 bytes
SHA-256: dff0df93fba0cef7d4dcdc2871e6897790fa6d348074ae315e07f74e4f88834b