Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef8ecea76f9cbb7e…

MALICIOUS

PDF

80.1 KB Created: 2021-06-10 23:12:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: eeca8b11a6c870ca4c1bb284e09dc946 SHA-1: 44c64f1ce43acc880203841f91f9d1f3cce8996e SHA-256: ef8ecea76f9cbb7e1f54f70627db2a5a070e51dccd6595142b5653e5aacd418c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous external links, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed for phishing or scamming. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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=acls+pretest+rhythm+answers
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/374e61daa73833c46611661c1aeb325c/28482310262.pdf
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160be827556aaf---sekuvesipewez.pdf
    • http://allycatering.com/userfiles/7237908159.pdf
    • https://west-holding.com/userfiles/file/xumebajobuxavofixigigula.pdf
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/4sm6440qk3fslitmji4jn5mttf/wabagiwulukaxivodokotafix.pdf
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b21a73b5c93---6927626238.pdf
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/3a16c0fe1c0e2c174189499baf3d1b7c/63287161358.pdf
    • https://www.paparazzirestaurant.com.au/wp-content/plugins/super-forms/uploads/php/files/38787217332d749f548ecdf32c579617/86911446012.pdf
    • https://rhagro.com.mx/wp-content/plugins/super-forms/uploads/php/files/8fb6f0b1ca0f49c0a67063cf86d3ec64/noxixawupan.pdf
    • http://stolizstekla.ru/userfiles/file/diwatavaxukitabexej.pdf
    • https://betentour.com/sites/default/files/file/nilowelogixoragiv.pdf
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/sl911s63bloggp7rn5f4cpklnr/kabakowetezewonomaz.pdf
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a00507cfef---lanurexovewemajevug.pdf
    • https://mvservice.it/file/najuzejigamef.pdf
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aaceeed52cf---pobowevawajozitopopoka.pdf
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/18a80fe3b96da1acfe9d9fcd378b9449/63059760789.pdf
    • https://teenvolunteer.org/wp-content/plugins/super-forms/uploads/php/files/b59383a4014322b4c4ee0f77df9476af/luneti.pdf
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16093fc069cbe5---vokegipegezipodebejutus.pdf
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a8d110c11a7---26561249386.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f8fe.bin
46a0059ba25cfd4ce29d75941d5bdf877a9ec3a5f1798301a3c23b1928219979
pdf-font-stream PDF embedded font (sfnt) at offset 0xF8FE 5356 bytes
font_01_sfnt_off00010b1c.bin
5dc94bfd27f2f9a3f2c5afd1be1cee46223b2d28482b7531cb7d33d766d43cdb
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B1C 11696 bytes