Malicious PDF — malware analysis report

Static analysis result for SHA-256 77c7719847676754…

MALICIOUS

PDF

83.5 KB Created: 2021-09-14 16:02:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 37a00d3bbe76f419b80fa080250feb31 SHA-1: abca0acf9e3988ca573cba9998dbe72a21041cbb SHA-256: 77c771984767675453ca444dab95ba979f034032e59fd1136ca7f1bac659010a
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm or SEO poisoning attack. The document body is heavily obfuscated and unreadable, preventing a more detailed analysis of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://agrocare.hu/ckfinder/userfiles/files/65538736613.pdf In PDF document text
    • http://elskup.pl/images/assets/file/zokofiwinozinix.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139c7c9ed76c---30015257139.pdfIn PDF document text
    • https://ijp2.com/contents/files/zixovogedezalenik.pdfIn PDF document text
    • https://nordavril.com/userfiles/file/xurinemuxodofatofabafow.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161337a90f1b01---41285170112.pdfIn PDF document text
    • http://www.santabriganti.org/admin/ckfinder/userfiles/files/nevinolax.pdfIn PDF document text
    • http://sysquare.com/UserFiles/files/34998700962.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/6857613e13ceaaa21e6fbe60293ebc7d/35947694243.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/161409c6de2e2c---55865263818.pdfIn PDF document text
    • http://tcsklife.com/filespath/files/20210909120458.pdfIn PDF document text
    • http://erulingua.hu/uploads/content_files/files/raxuziraduv.pdfIn PDF document text
    • http://tuzvedo.hu/elemek/file/venigabunimiwotoridu.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613919f6101e3---40938740749.pdfIn PDF document text
    • http://maximaviajes.com/FCKfiles/file/kuwijop.pdfIn PDF document text
    • https://plasy.com/uploads/file/tefubirenakeb.pdfIn PDF document text
    • http://ticketsperiodico.com/galeria/files/71132612326.pdfIn PDF document text
    • http://www.neoneophytou.com/ckfinder/userfiles/files/purituxomubukubulopali.pdfIn PDF document text
    • https://artofsurfing.com/preview/ckfinder/userfiles/files/jatulafegadimogepowoliro.pdfIn PDF document text
    • http://elvirajogsi.hu/ckfinder/userfiles/files/52918541518.pdfIn PDF document text
    • http://hoya-system.com/uploads/files/202109121256317900.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/76b34993ede1eac7d4fbbc2164db2dfd/40424867450.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613245abcfca1---12463566.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=vnrom+bypass+account+2019PDF 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_off0000e0b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0B9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f8d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8D0 11048 bytes
SHA-256: 5b290d6247e1ed5466c6db7aee795055e53fa3c06d5d62bb0b306f320a26c47a
font_02_sfnt_off0001127b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1127B 18112 bytes
SHA-256: 3e27fa6ae5a4da993fa6cb2582124bd15d01361b7f6818c1b3444b1dc3c882c9