Malicious PDF — malware analysis report

Static analysis result for SHA-256 87f9cd7ee600b73e…

MALICIOUS

PDF

88.6 KB Created: 2021-09-03 20:04:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c496350adbf247284762f14f734621a1 SHA-1: 9c33fc80f6e535316498a7d4bc8d73b163290fc7 SHA-256: 87f9cd7ee600b73ee3250ad9506b7df2c62c0ac92595e177aabc9effae1b9eb4
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to external files on compromised or disposable hosting. Heuristics indicate this is a link farm, likely for SEO manipulation or to distribute further malicious content. ClamAV detection as 'Pdf.Phishing.Trojan' and ML classification strongly suggest malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 https://agatanorek.com/files/file/23932048956.pdf In PDF document text
    • https://idd.no/ckfinder/userfiles/files/10716536354.pdfIn PDF document text
    • http://denda.co.kr/ckfinder/userfiles/files/zinulufafarevini.pdfIn PDF document text
    • http://saopauloairporttransfers.com/ckfinder/userfiles/files/23480389416.pdfIn PDF document text
    • https://www.aicsmindia.org/ckfinder/userfiles/files/nazimiduxovorukavinovokej.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608efc08751cd---forosigedap.pdfIn PDF document text
    • https://balbok.net/admin/ckfinder/userfiles/files/fagukifejodubuzag.pdfIn PDF document text
    • https://blsautomation.com/ckfinder/userfiles/files/rokelokufasipawoteratu.pdfIn PDF document text
    • http://forumts.com/ckfinder/userfiles/files/rabowug.pdfIn PDF document text
    • http://bestorkate.com/uploads/ckeditor/files/zozewumog.pdfIn PDF document text
    • https://bestcaps99.com/ckfinder/userfiles/files/tekulumizenise.pdfIn PDF document text
    • https://giridhareye.org/ckfinder/userfiles/files/73389231495.pdfIn PDF document text
    • http://uralinteh.com/uploads/files/wejunepi.pdfIn PDF document text
    • https://sketchup360.vn/wp-content/plugins/super-forms/uploads/php/files/9n8gd76s9ii98cj7bnn9cbmeda/47248235301.pdfIn PDF document text
    • http://vmkmsz.hu/userfiles/file/27314146555.pdfIn PDF document text
    • http://saipanbooking.com/FileData/ckfinder/files/20210626_4D354B101DFE856B.pdfIn PDF document text
    • http://ngnjl.com/userfiles/files/nizuxomebexuxasupowow.pdfIn PDF document text
    • http://top1np.com/ckfinder/userfiles/files/86550782992.pdfIn PDF document text
    • https://samudra99.com/contents//files/60755753861.pdfIn PDF document text
    • http://hotstamping.pl/files/file/famifakebe.pdfIn PDF document text
    • http://vietthanhstone.com/images/news/file/zususenaxelisurajodefob.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160ae8da4c240d---70173773992.pdfIn PDF document text
    • http://debsecond.net/UserFiles/File/47711363478.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=radiological+anatomy+textbook+pdfPDF 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_off0000f3f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F3 11188 bytes
SHA-256: 6975d11fb3d44591d9b556d49367be504ae78a0109e9f4466c598460aa82cdb1
font_01_sfnt_off00010db4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DB4 17900 bytes
SHA-256: 70db450793e814caa6ae7435b284e52850077b3710cb00950c47b11c3aaeb6d4
font_02_sfnt_off00013c7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C7B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1