Malicious PDF — malware analysis report

Static analysis result for SHA-256 2bc92755270de0a6…

MALICIOUS

PDF

73.9 KB Created: 2021-09-03 13:16:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 4d928b5994a980e9d83b24da3db66f12 SHA-1: d6eb40f1e82e8734cb27da2f0ffacdbe1cd8faff SHA-256: 2bc92755270de0a6992c889a7f116c2a234fb657a4744f38f276a5d6a569ebfb
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted from this sample, but the extensive use of external links is the primary attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://infrive.ru/uplcv?utm_term=tn+school+books+pdf+free+download PDF link annotation
    • http://waypl.pl/upload/File/filubidawevozewuvebedizow.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/a01ecfbd306a2f618dbb3d6d60188330/65524001603.pdfIn PDF document text
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/11e75r4r7vgdbi3q51teaj8pd5/kuxijufalumepifapinolugut.pdfIn PDF document text
    • https://sbmhavacilik.com/userfiles/file/xerapokudiwutudewur.pdfIn PDF document text
    • http://hzzxtl.com/UploadFile/file/20210619184337463.pdfIn PDF document text
    • https://skazkavdom.com/wp-content/plugins/super-forms/uploads/php/files/cd4e3639d5733afe02f631a4d2edd677/tobixisa.pdfIn PDF document text
    • http://4chan.ro/UserFiles/file/48400713262.pdfIn PDF document text
    • http://email-database.info/userfiles/file/dokirorenelav.pdfIn PDF document text
    • http://physocare.com/Images_upload/files/45361315835.pdfIn PDF document text
    • http://notariocprietoa.com/notaria/documentos/files/68533414311.pdfIn PDF document text
    • http://expertsystemgroup.com/file_media/file_image/file/10943641624.pdfIn PDF document text
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/3349b149c6fe44d08d2cbb23aade1bda/36276831416.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/19244771416.pdfIn PDF document text
    • https://grupo-bahia-real-estate.com/ckfinder/userfiles/files/kamibu.pdfIn PDF document text
    • https://www.sudburyhighspeedinternet.ca/wp-content/plugins/super-forms/uploads/php/files/86d4c7702ec03162bc75260744164431/89572787120.pdfIn PDF document text
    • http://96rangjai.com/userfiles/file/defivumilajagalida.pdfIn PDF document text
    • https://www.brightfieldbusinesshub.co.uk/wp-content/plugins/super-forms/uploads/php/files/km7bdajq6uld1gdkbq28simq4t/paxodoba.pdfIn PDF document text
    • https://gameclub.by/uploads/files/11185017731.pdfIn PDF document text
    • http://anhbanglaw.com/userfiles/file/90126201782.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082313fd9287---zofurunowitofu.pdfIn PDF document text
    • http://maurovalleferroarchitetto.eu/userfiles/files/47824707632.pdfIn PDF document text
    • http://pericosrentcar.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160968e27cfc45---fipuwulotomakoxuvipu.pdfIn PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612340d0b51da---45707288095.pdfIn PDF document text
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/e4ce948bb4c1edbe887c0b302134becf/94773146067.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_off0000b96a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB96A 18340 bytes
SHA-256: 6bc5e3f2b93634b99c4cfc069acb94e0bec062fa5259b58f3459b44b787f84da
font_01_sfnt_off0000e91a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE91A 10808 bytes
SHA-256: ce556a6d516fcdd74f1f906d799e7924151808d15d28d65b711f4fff7fa2c4d8
font_02_sfnt_off000101cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101CB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1