Malicious PDF — malware analysis report

Static analysis result for SHA-256 3e20b1071edfc3fb…

MALICIOUS

PDF

74.1 KB Created: 2021-06-25 15:45:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: acfbce1d14d4974aed28da225503d342 SHA-1: 52afd9e20f1ff56528585fed9b52ed96f1e7fdda SHA-256: 3e20b1071edfc3fb6a6bc572971f55bb3791b8b850e1e7201a4fe112491aaa29
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous embedded URLs that point to compromised websites. These sites, in turn, host further PDF files, suggesting a multi-stage attack designed to lead the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://alphaveneers.co.uk/wp-content/plugins/super-forms/uploads/php/files/305637babe6bf6b75fa916c9ea0f8dd0/67017844468.pdf
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/3ab7b58eb161ef1c0858a4f1ca0b99c6/76382082790.pdf
    • https://srp-galabau-rostock.de/wp-content/plugins/super-forms/uploads/php/files/g4cg7rd1d2bo350eiihh8lk530/waxonevodutus.pdf
    • http://gat-asset.com/CKEdit/upload/files/nebamobaxumotisepaxixer.pdf
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/em447mfi83flg5bmcqdvpop0v8/kilukotidemizug.pdf
    • https://daleplumbinginc.com/wp-content/plugins/super-forms/uploads/php/files/25f035ecb4a89505ce7de00de4ba7f0a/33423757978.pdf
    • https://oiweld.com/wp-content/plugins/super-forms/uploads/php/files/0cc51255743be4ff7ceae5bb70e82234/lotexelalomafev.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609091ba4822b---32706065109.pdf
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b83636adb61---xisudenop.pdf
    • http://naturallabs.fr/userfiles/file/gurubenuko.pdf
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/ob0hqe2ji8tn6ese8i8u0gj6k0/39563888823.pdf
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/8c968c2af776daf7fe62c7121471c6d2/gevubopuxozejaniti.pdf
    • https://observatoire-omic.org/documents/file/36613573287.pdf
    • https://intrigantka.ru/images/userfiles/file/51583060992.pdf
    • https://callhfelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad89634cb2c---poguto.pdf
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/da1691a3079b2664020063c600c7d036/tofapisuxojubemorasiwufax.pdf
    • https://xo-sound.ru/userfiles/file/tonizodoxixuze.pdf
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d797e6adbc---16460344323.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=even+number+definition+with+example
    • 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_off0000ba80.bin
3e58c160acbf4d87be36768acf504ee96defebac796210920a791543f270cb4e
pdf-font-stream PDF embedded font (sfnt) at offset 0xBA80 18108 bytes
font_01_sfnt_off0000e9e3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE9E3 16792 bytes
font_02_sfnt_off000101fa.bin
eacea6fc0e91329127bab5fb3d44a778d6fd8b0684e496ac36bacbbd14afb3c2
pdf-font-stream PDF embedded font (sfnt) at offset 0x101FA 11072 bytes