Malicious PDF — malware analysis report

Static analysis result for SHA-256 51ba09a55f9addb8…

MALICIOUS

PDF

84.2 KB Created: 2021-10-15 03:23:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c72df6949b754c12dbd94943e3bb1fa2 SHA-1: 42069ce0f9f60d8b8a9d661bc6a1e9e6d1e45016 SHA-256: 51ba09a55f9addb8b1456fdbd8276804026e943354c62b97a104ad7e55d558c1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised CMS upload storage and disposable hosting, suggesting it's part of a link farm designed to redirect users to malicious sites. The presence of embedded URLs and the nature of the heuristics strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7513

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://segurosjdd.com/wp-content/plugins/super-forms/uploads/php/files/mfe5potjjv683d335iasrhv9p2/putewobipediw.pdf In PDF document text
    • https://lifesmart.lifesmart.ro/ckfinder/userfiles/files/97507087488.pdfIn PDF document text
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/16155e57f77620---nodeguzemonijaxun.pdfIn PDF document text
    • https://gregoryshow.ru/files/file/vuxemaxevagetuweximej.pdfIn PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/pvevrun35fg1do4uo87vvabp35/92820358225.pdfIn PDF document text
    • https://medarbindia.org/ckfinder/userfiles/files/78183018345.pdfIn PDF document text
    • https://chorland-dining.com/webroot/editor-uploads/files/63313043536.pdfIn PDF document text
    • http://teknis.it/userfiles/files/jewiki.pdfIn PDF document text
    • https://webkapper.nl/ckfinder/userfiles/files/16979859754.pdfIn PDF document text
    • http://sunmoon-glory.com/web/upload/files/gimaxobodaduxi.pdfIn PDF document text
    • http://saigondome.com/uploads/userfiles/file/83477340116.pdfIn PDF document text
    • http://mesterteto.hu/userfiles/file/42393987160.pdfIn PDF document text
    • http://lifecare4all.com/upload/files/17340883183.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/161462081efcbb---37058094166.pdfIn PDF document text
    • https://mmeasar.com/mmeasarfiles/file/jorefib.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/161686c7d3c1b3---suwupodakuruzulixoteriwub.pdfIn PDF document text
    • https://amthanhanhsangchinhhang.vn/upload/files/kotenomerutemalos.pdfIn PDF document text
    • http://fxmeat.com/upload/file/e987d98661fab4f848fa67bbf056ceb3.pdfIn PDF document text
    • http://nincity.de/inline/file/61835878466.pdfIn PDF document text
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/0412238484e846644699b49b0ca397d2/jofoliguxujuxag.pdfIn PDF document text
    • http://briztravel.com/upload/files/30755058563.pdfIn PDF document text
    • http://fsf-vastroad.com/userfiles/file/48607520821.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/6692c5ea48b9d682dbe29163549586fd/11826069497.pdfIn PDF document text
    • https://jvlegacyhomerepairsmd.com/nbloom/fckuploads/file/58462698857.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/rlbn95h96q6aei188d12obqlsm/gavujisezabexudamivab.pdfIn PDF document text
    • http://feedproxy.google.com/~r/MbOu/~3/tgwjJlsMqHc/uplcv?utm_term=how+to+build+a+dungeon+book+of+the+demon+king+animePDF link annotation
    • 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_off0000eced.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECED 10940 bytes
SHA-256: 632d5990cd2ddb5c285435e2f470955df38bc73f2db91aec21f88086c096c7b1
font_01_sfnt_off000105de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105DE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011df0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DF0 18792 bytes
SHA-256: f24302618a102809c4fe343427af191783f6e28caba32dae4dd51a8f76810368