Malicious PDF — malware analysis report

Static analysis result for SHA-256 53163d795aa4cb70…

MALICIOUS

PDF

86.1 KB Created: 2021-06-25 22:02:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: aa0a28498d955850999d4821cf718ee6 SHA-1: 43835765ed8f8ec2d8b730ae90e301b16b3674aa SHA-256: 53163d795aa4cb70ec578676943444bb95b310fddd184a08a2a78028ee112aa6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, with numerous embedded URLs pointing to compromised websites and disposable hosting, likely to lure users into clicking malicious links. The presence of multiple distinct hosts and the use of UTM parameters suggest an attempt to obscure the true destination and potentially track user engagement.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

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 https://cochleartudaskozpont.hu/files/1508402686.pdf In PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a3ef692f15---73971124609.pdfIn PDF document text
    • https://propertiproperty.com/Uploads/userfiles/files/morowanetu.pdfIn PDF document text
    • http://xn--clinicaquirogavilario-vbc.com/wp-content/plugins/super-forms/uploads/php/files/cfsq7a2ij52na8b02ns3ge9eg7/nujedepenipilokawororukub.pdfIn PDF document text
    • http://skyline1968.com/clients/74864/File/11921527385.pdfIn PDF document text
    • https://botorka.ro/userfiles/file/2224009453.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/d2837bab647196c3a88e17042956d5da/tajepeluwefizijironenogo.pdfIn PDF document text
    • http://slbreakingnews.com/ckfinder/userfiles/files/84812169415.pdfIn PDF document text
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607bbd7a11636---bewugisadefolerebuzepuxej.pdfIn PDF document text
    • http://splogservice.ru/content/file/626268968.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d23ea03629e---2566487718.pdfIn PDF document text
    • http://altaprecision.com/userfiles/file/71248169036.pdfIn PDF document text
    • https://gea99.com/ckfinder/userfiles/files/91138381446.pdfIn PDF document text
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607086da800b1---53250988806.pdfIn PDF document text
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609417037aa50---40709979279.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/160947740ac52b---95947196918.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/e376b0f2c7dc3aae5300203e94c7f0d9/nexovugowizar.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/160754fa5af65d---xirolunanukafixopevape.pdfIn PDF document text
    • http://www.iece.in/userfiles/file/57212427184.pdfIn PDF document text
    • https://www.travelticket.com.au/wp-content/plugins/super-forms/uploads/php/files/9fqiu4bnf8im5n1gainr7j93ot/11816699523.pdfIn PDF document text
    • https://askisan.com/upload/ckfinder/files/namovisagixi.pdfIn PDF document text
    • http://fogathajtohirek.hu/fckfiles/file/xexevigobigolu.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e036a46b2d---63577840097.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/a9d2c07db78d83be3f8cc8b20280e213/70363360341.pdfIn PDF document text
    • https://wpsqld.com.au/wp-content/plugins/super-forms/uploads/php/files/26cc1944221ebac1d658bf282620e1c5/bapelov.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=chemistry+practice+problems+answersPDF link annotation
    • https://sharpspringwww.kinsta.cloud/wp-content/plugins/super-forms/uploads/php/files/1ca388c8dc321e0c228f2e3181a72728/9996471007.pdfIn PDF document text
    • 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_off0000ebf0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBF0 17316 bytes
SHA-256: e9aee70ce1a9d0c30f74a2f141137c6e7bd913ea7373af0cecc5c6cc09bfb6c9
font_01_sfnt_off00011970.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11970 11008 bytes
SHA-256: edddd6dd4670e99359fcb558148eb6ad6eb9148c8d654773d671ffe84192f071
font_02_sfnt_off000132b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132B8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1