Malicious PDF — malware analysis report

Static analysis result for SHA-256 4903b31b21bd91a2…

MALICIOUS

PDF

86.0 KB Created: 2021-07-14 08:27:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 889e441db6b94f5e8d8b8efd97b9fdea SHA-1: 2bc459e6504ac16bb754d312ae70f7cd9ad1fcd8 SHA-256: 4903b31b21bd91a229e7ee16c0c5c1a125d8b1e11bec6ad115f27c599b57343d
156 Risk Score

Malware Insights

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

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress upload storage, suggesting it redirects users to a secondary malicious PDF. The presence of numerous unknown URLs further supports this, as they likely host the next stage of the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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 http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160da4279ba494---6878888278.pdf In PDF document text
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/n89eegmf7hfkkf293rl6j88pt5/61936256439.pdfIn PDF document text
    • http://symbioticlifetech.org/attfile/fckimg/file///2021051094759_68540738.pdfIn PDF document text
    • http://kuhomania.ru/ckfinder/userfiles/files/45715559154.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/16093c85b03b2a---12438059343.pdfIn PDF document text
    • http://ballarioarchitetti.eu/userfiles/files/fafizamojigok.pdfIn PDF document text
    • https://acgroupenterprise.com/userfiles/file/84965547111.pdfIn PDF document text
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/160810aa569c88---lowasafuto.pdfIn PDF document text
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/80f77agjt897gv3oc4ve6btsc5/wuziliwobizatixenewow.pdfIn PDF document text
    • http://longarmquiltacademy.net/fckeditor/userfiles/file/40005033014.pdfIn PDF document text
    • http://al-bandak.com/userfiles/file/67220256003.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094dd531e5a0---vajotekuziwasesosa.pdfIn PDF document text
    • https://area34.info/wp-content/plugins/super-forms/uploads/php/files/4bmllp6nbs4pi1v4r8didm52o7/94287727578.pdfIn PDF document text
    • https://papiratisk.cz/soubory/nikesutufasinosu.pdfIn PDF document text
    • http://nguyenthaotech.com/upload/files/46319892508.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160986de0cb90d---2639022092.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/86ae165d70b332ff41a0e2d1d56f8b77/giridaruposafifiwukur.pdfIn PDF document text
    • https://alkalacarservice.com/public_html/userfiles/file/58487966875.pdfIn PDF document text
    • https://smilepath.com.au/wp-content/plugins/super-forms/uploads/php/files/785acc7e7ba6a390f234f24b916f9f88/49221593786.pdfIn PDF document text
    • https://www.idahomedia.com/wp-content/plugins/super-forms/uploads/php/files/6f7a3c2a7fc769f46f6debe16dc65d13/15127458308.pdfIn PDF document text
    • http://arenda-v-novosibirske.ru/ckfinder/userfiles/files/vafura.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=septicemia+in+cattlePDF 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

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eef3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEF3 10224 bytes
SHA-256: cb8bf00be2d5e1064c5929e8a8f8abba9bd3574ae389371cc131db0e76593a39
font_01_sfnt_off000105dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105DD 17268 bytes
SHA-256: 026dd4bb739b6f485af2791a2689139d2f5786f6ed0b97a245b4d88e57dd106e
font_02_sfnt_off000131ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131EE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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