Malicious PDF — malware analysis report

Static analysis result for SHA-256 871992d65ebb1bbb…

MALICIOUS

PDF

83.3 KB Created: 2021-07-18 11:20:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: 2c640019c0d13d00e67cd40cbaa9c6d3 SHA-1: d10de50e1cd4b0a6315a7885953e47688212d76e SHA-256: 871992d65ebb1bbb4da1bfc5647c579f3cf264d81b25203e2806b227f1cad094
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a callback-phone (TOAD) lure. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 7

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://zulapin.com/calisma2/files/uploads/92957156309.pdf In PDF document text
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b294be9eaff---mofefogaberav.pdfIn PDF document text
    • https://monuments-msk.ru/wp-content/plugins/super-forms/uploads/php/files/86773912d32770f159feabda9f075b05/11673079423.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160870c81257c2---mitupaj.pdfIn PDF document text
    • https://indacphuc.com/wp-content/plugins/super-forms/uploads/php/files/98dn6oj2gbfp40plf9s534phte/kasogaduwakutulim.pdfIn PDF document text
    • https://condominiovillage.com/userfiles/file/65161298552.pdfIn PDF document text
    • https://bluetact.com/locktactyuma/userfiles/file/mutirezemubinupagi.pdfIn PDF document text
    • http://jfac.kr/ckfinder/userfiles/files/rofewosikotegunififemeb.pdfIn PDF document text
    • http://brandiassociati.it/userfiles/file/95528512341.pdfIn PDF document text
    • https://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/a2a1e1d4d7387e7ddd7d7cd31e32d205/dobubedupedinufiruf.pdfIn PDF document text
    • http://www.misshandicap.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16075b02d8d182---mepunifawuwovabojokador.pdfIn PDF document text
    • https://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/cldr7tdtiuokds3lvfi7ijaboh/71662828504.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/160becb65e51c0---mulibovavesuj.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d54217956e---molipanolomexapezaton.pdfIn PDF document text
    • https://www.apartamentselsllacs.com/wp-content/plugins/super-forms/uploads/php/files/oahu3v5ibo0313q4mv5rm5aabl/57006589028.pdfIn PDF document text
    • https://barcelonacentremedic.cat/files/galeria/files/78348589074.pdfIn PDF document text
    • http://50wj66.com/clients/a/af/af9d65f11c1965a5434adcd4cd578f00/File/1371365024.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/838dddb5e8f3ee30d59a428d51b91ffd/watomowisiwiko.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ef26abe67b---72805205182.pdfIn PDF document text
    • http://aleeblog.com/wp-content/plugins/super-forms/uploads/php/files/32rd8li6c2cqnpko8f31h45jo4/33528379577.pdfIn PDF document text
    • http://www.orhancoskun.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6f9f05790a---ripavoxidifewanoxezomeba.pdfIn PDF document text
    • http://sunjewelsonline.com/userfiles/file/45946096763.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/guwifuful.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=c%23+net+interview+questions+and+answers+for+freshersPDF 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_off0000e92f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE92F 17016 bytes
SHA-256: d9d1ab500365bb6da0ad9d3195eb8f6930820ad3108f550a8871940406e44104
font_01_sfnt_off000115cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115CC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012de2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DE2 9104 bytes
SHA-256: fe4a9ad32d6d12da45ce8861a1e6e511df5579fd33367a5c4d1c9e774d301804