Malicious PDF — malware analysis report

Static analysis result for SHA-256 510783a9d03b9b6d…

MALICIOUS

PDF

94.8 KB Created: 2021-06-25 12:49:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c8aabc8c4305d73b111a9528daf1685a SHA-1: 31a55e3629e4d39d68e2078f7add8afb81b38b43 SHA-256: 510783a9d03b9b6dbf1cff404b7065934d70bae2789f6079d9e1a72b4d95166b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to compromised WordPress sites and disposable hosting domains. The embedded URLs suggest an attempt to distribute further malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://cructi.ru/uplcv?utm_term=business+acumen+performance+review+phrases
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098ef08301cf---75199510173.pdf
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073a8e224abe---54122656538.pdf
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/meqsruojus719qdma40nh0for1/85673857399.pdf
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c0856391c8b---xibozonogesunajizafo.pdf
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0c35ca0568---zavisebosi.pdf
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd507de1ab0---8096321267.pdf
    • http://starlightcelebre.org/clients/4/43/43e9139217482d7666ce300faf566241/File/tofok.pdf
    • https://winston-woodward.com/wp-content/plugins/super-forms/uploads/php/files/26f8b97d0ba2430d8767fa4db6bc49c2/23458102547.pdf
    • https://www.northwoodmedical.ca/wp-content/plugins/super-forms/uploads/php/files/p76bqt2jbsvqirtsq1tdkcbqmf/85616024065.pdf
    • https://pnp-studio.com/fckeditorfiles/file/zuwep.pdf
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b72872834cc---21539097291.pdf
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/160bde5fc8d441---jikitowuvupinap.pdf
    • http://maidnheaven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bdf53e8f2a---94233068465.pdf
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/4d8a8ef1548b4c5433e6632e8a1364e4/jinegafaf.pdf
    • https://robotics-institute.com/wp-content/plugins/super-forms/uploads/php/files/hc66qquje6etighbflhac1rmv1/79353532249.pdf
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1606d9b92b1107---mokegugoxetaropifobelejuv.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160aa25efe04ed---88276370690.pdf
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16095f3cf9e209---fukobeke.pdf
    • 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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011066.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11066 16792 bytes
font_01_sfnt_off00012878.bin
1c4bd68e567387fbc7c793fc78174be1e7cea90d35fbdb8dad15788b74a2ad20
pdf-font-stream PDF embedded font (sfnt) at offset 0x12878 17108 bytes
font_02_sfnt_off00015500.bin
cdaa65c39d994f74e56a4ef64c8e3a205204f1781136f9229f385b04c74f329d
pdf-font-stream PDF embedded font (sfnt) at offset 0x15500 10908 bytes