Malicious PDF — malware analysis report

Static analysis result for SHA-256 bcf1a99334ad3db3…

MALICIOUS

PDF

79.7 KB Created: 2021-09-03 22:31:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c4e417029da3de69081ea00f37c60d05 SHA-1: 5eae6405d883db2d2aacf6cc6e7ff551653a437c SHA-256: bcf1a99334ad3db3c5f2cf64cfab651ab6db4ca3177e608176a7ac11a5f7dc88
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or to serve further malware. The file's structure as a link farm on disposable or compromised hosting further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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=v.c+kapoor+taxonomy+pdf
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a536f826f0---vufaveg.pdf
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca35e6a99a---lobelelugadi.pdf
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/44baa73b1871774e31f527f6fffdaaf6/pagiraziliwuvawaloganade.pdf
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/vmtchqf7bnd21fckflttir6vs1/moseradobejiruxagum.pdf
    • http://altelaw.com/uploads/image/file/negal.pdf
    • http://www.ez4parcel.net/upfile/files/2021/08/09/89125238709.pdf
    • https://bamor.org/userfiles/file/36894811949.pdf
    • https://digireg.pl/upload/bagepazuzore.pdf
    • http://ck-kutnahora.cz/gais/image/file/79213669579.pdf
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/xujid.pdf
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cbac114d4bb---28489269702.pdf
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/c180db740fdee1a01eced059d35c48f3/vevavidokevadiso.pdf
    • http://biancoacolori.it/userfiles/files/89885419223.pdf
    • http://polipadel.com/userfiles/file/jijuwodijo.pdf
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/fbf4bab40cd496aff4ed23fd6cd5076a/16559795840.pdf
    • http://diysmart.net/userfiles/file/wototofunogenerame.pdf
    • http://goergenpainting.com/clients/0/0d/0d1038892961fdbf96b6a8e7e8daca8f/File/42083035365.pdf
    • https://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/6876268142a58f5d53bc64b6e1d10fbc/popotedavob.pdf
    • http://aiswaryamatrimonials.com/fck_uploads/file/63824846807.pdf
    • http://valsadindustries.com/userfiles/file/muxugowaroretixubani.pdf
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608fda116465b---50348256601.pdf
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/88543c34dfcc37b419d4020590371ed0/74895299092.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_005_off000118d7.bin
65ec3de44c6767b8e65203987ef3fdcb051680f0a6e754af9a448a5e13c569ec
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x118D7 16888 bytes
font_00_sfnt_off0000ba8e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBA8E 16792 bytes
font_01_sfnt_off0000d2a0.bin
b667a2abf881c55716966563fdaf0d7a1ccd6ab08b4eb1ed2cf0a662cc0b52e9
pdf-font-stream PDF embedded font (sfnt) at offset 0xD2A0 17608 bytes
font_02_sfnt_off00010040.bin
da9d174306749c192e2f5e28177ece98557c5a004dd8db8b0fdedb36477ae142
pdf-font-stream PDF embedded font (sfnt) at offset 0x10040 10684 bytes