Malicious PDF — malware analysis report

Static analysis result for SHA-256 427ef5c83a6a584f…

MALICIOUS

PDF

78.0 KB Created: 2021-09-02 12:20:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: eb61681b7c0613b258be0d62469dfb10 SHA-1: 3a905ed27d6d3c977d5c9b59e5f0ddda2c3ffcde SHA-256: 427ef5c83a6a584fc694e48d01136580796d849903724c0548012f65222eef16
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites acting as link farms. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery. While no scripts were explicitly extracted, the PDF structure and embedded links suggest it's designed to lure users to external, potentially malicious, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • 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.
  • 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://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d0422b3fa1---depixidagupa.pdf In PDF document text
    • https://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/b9beien2le32tuttsg6r0mm6s1/wiwulepafumifozofuliboj.pdfIn PDF document text
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/766qdu9gel01v2q77o5abo9ib4/99357591549.pdfIn PDF document text
    • https://nnkcreations.com/userfiles/file/57283368693.pdfIn PDF document text
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7ffa8c67c---momaroj.pdfIn PDF document text
    • http://alotercuman.com/ckfinder/userfiles/files/47697100907.pdfIn PDF document text
    • http://secretinvitation.net/images/files/83882467207.pdfIn PDF document text
    • http://www.ssc-ras.ru/ckfinder/userfiles/files/54933917709.pdfIn PDF document text
    • https://soosekszer.hu/upload/files/lasenego.pdfIn PDF document text
    • https://flying-vikings.net/UserFiles/file/93190008479.pdfIn PDF document text
    • http://chi-kara.net/userfiles/file/rulokebos.pdfIn PDF document text
    • http://hzkontejnery.cz/ckfinder/userfiles/files/472641216.pdfIn PDF document text
    • https://etonbio.com/newsLetters/images/file/zanejitixome.pdfIn PDF document text
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/e41050f1549755a592ad75b5f479a2b8/95912847630.pdfIn PDF document text
    • https://investainternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606dfb228e3e5---gokededajuzexenanorav.pdfIn PDF document text
    • http://alfadent-volg.ru/images_uploads/files/8472407828.pdfIn PDF document text
    • http://ttlh.vn/storage/ckfinder/files/sudatufitofupu.pdfIn PDF document text
    • http://korean-school.hu/hangul/userfiles/file/fipabipinidesipuw.pdfIn PDF document text
    • http://styropapex.pl/userfiles/file/89571326321.pdfIn PDF document text
    • http://rayer.cn/d/files/45705496877.pdfIn PDF document text
    • http://lowry-averyreunion.com/clients/c/c0/c0e4e7922159a76f956c19110b7bfeb7/File/jaruxof.pdfIn PDF document text
    • http://hillsdale66ersreunion.com/clients/c/c6/c679c52642bc64dd8629b98fb95ccc77/File/4729460335.pdfIn PDF document text
    • https://renebeumer.nl/userfiles/file/36060586019.pdfIn PDF document text
    • https://austarpharma.com/upload/files/zosesutixe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=manual+jeep+compass+2017+portuguesPDF 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_off0000cacc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCACC 11192 bytes
SHA-256: 4d9ff2d85c0bbcf326b07d6dcc78328ebeb68ae1bfc205e830047f0e55ba7dd1
font_01_sfnt_off0000e528.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE528 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fd3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD3A 17472 bytes
SHA-256: ab9438f427a62fdd4cc408175afabbf9033bb21d6725ca942702598a2d89cc02