Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b1053a9fbe3d3c5…

MALICIOUS

PDF

77.8 KB Created: 2021-09-02 06:49:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 17ff0aaeb4e1bb0898fbe4710ddf5308 SHA-1: 7d0cdf58b27af2156c41997580fd553139141775 SHA-256: 7b1053a9fbe3d3c54ce1dac2b1a6ecfe98bbf7b8d11e95522f2d9d2edb5f6ec2
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript and a link farm pointing to multiple distinct hosts, many of which appear to be compromised WordPress sites. The primary purpose seems to be redirecting users through these links, likely to a phishing page or to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://premiumvipbusiness.com/wp-content/plugins/super-forms/uploads/php/files/b7d268abcf7e82eaf7309a778b84e20d/wezije.pdf In PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/16082d7da4ffc5---sujovagawewazota.pdfIn PDF document text
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/rlier1qlcslgm0im7th7s6l0tt/74740045141.pdfIn PDF document text
    • http://fine-cottage.ru/userfiles/file/komatatinigidujijutawur.pdfIn PDF document text
    • https://nsck-cykelmotion.dk/userfiles/file/sugubasubunalafedota.pdfIn PDF document text
    • http://koopmankennedyfeller.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/ferutuvudofozuf.pdfIn PDF document text
    • https://alutat.com/data/file/gelenudosokulazexiwasa.pdfIn PDF document text
    • https://www.sensormaticltd.com/app/templates/js/ckfinder/userfiles/files/45765990134.pdfIn PDF document text
    • https://eseninternational.com/uploads/files/51970299486.pdfIn PDF document text
    • http://csc0851.com/userfiles/file/20210816190550_ve44sf.pdfIn PDF document text
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/16079080f3e4ec---82741939567.pdfIn PDF document text
    • https://optimustelecoms.com/ckfinder/userfiles/files/supepiw.pdfIn PDF document text
    • https://envida-nieuws.nl/bsb_website/upload_fck/file/35136044061.pdfIn PDF document text
    • https://syntellect.ru/Repository/file/kozifamexurokawodu.pdfIn PDF document text
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b983a2c609---25280019438.pdfIn PDF document text
    • http://veribase.com/E/file/zisitilineta.pdfIn PDF document text
    • http://nenorm.com/files/files/xidovidugana.pdfIn PDF document text
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/q2ri69j6tqq3236actkrpk9gpp/bewamamolofimazililuro.pdfIn PDF document text
    • http://tetobox-budapest.hu/uploads/files/jomumetomajeruno.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160967fd6f28e2---58579366188.pdfIn PDF document text
    • https://1snrpaulista.com.br/ckfinder/userfiles/files/zisimotitefi.pdfIn PDF document text
    • https://aksukartela.com/images_upload/files/dadewodato.pdfIn PDF document text
    • https://caribemed.com/userfiles/file/tudiwamogep.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=difference+between+curl+and+divergencePDF 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_off0000c847.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC847 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e059.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE059 18456 bytes
SHA-256: 29e7e14c6b497ab4a3f9b3c24b7d574e19b7ad023dd4301b4508d3d78d68478d
font_02_sfnt_off00011072.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11072 10756 bytes
SHA-256: 4fcaae0a004696895d84eb30f8953c6619ac4ddc044e292ac8c081926c2174d0