Malicious PDF — malware analysis report

Static analysis result for SHA-256 91b0e5bdb7ffd3e8…

MALICIOUS

PDF

82.0 KB Created: 2021-06-25 13:44:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 6bf24f1cb8bb419b1796a1bad49614d0 SHA-1: a26f5142661f5058b9a11dba0635e49ff494717d SHA-256: 91b0e5bdb7ffd3e84fa23158e744d352333585bd913196b74c9640ccf5b29e3c
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, pointing to numerous URLs hosted on compromised CMS uploads or disposable domains. These links likely serve as lures for phishing attacks or to distribute further malware payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://mg001.cn/upload_fck/file/2021-6-5/20210605043042489331.pdf In PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/81120fc9eafc19497348293cc1291277/kavijekinaduduwuguvobej.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/f4fbd8e8a61ea79ed3da93990af8e5f4/41138435811.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093aa95e509a---7675562042.pdfIn PDF document text
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7676986aa4---vexulimek.pdfIn PDF document text
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/2a3koprkgg7c6t3v4i9ft8ueb0/lubifakewigavivagoluxutav.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1607ad8c8e8f40---26186236968.pdfIn PDF document text
    • http://hzjksj.com/images/upload/File/fonamijepawukevovubukux.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160763a7adfcda---kutavububujavufewopaf.pdfIn PDF document text
    • http://5m-tti.com/uploads/image/files/fefopobogepadilarib.pdfIn PDF document text
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/591ecebb90a684954750200d752ed0d9/kijelilolez.pdfIn PDF document text
    • https://marblobaths.com/app/webroot/img/files/99195563599.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098359bf10b0---ruxowexuluwuburevitowibi.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/687f536057126ba608d3cd2775c88b1d/lelisod.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=all+religion+is+a+foolish+answer+to+a+foolish+question+meaningPDF 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_off0000d94d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD94D 10972 bytes
SHA-256: 147248b0c6ac81706c582e942fdabb3b14168d41fa98c1bdb9df52b9e3be6fd1
font_01_sfnt_off0000f252.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF252 19172 bytes
SHA-256: 43f6e78cab387e3b868d83b6da315fa6c9d1b4c6c7580ffa5ae86dab37bed6aa
font_02_sfnt_off0001230a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1230A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1