Malicious PDF — malware analysis report

Static analysis result for SHA-256 57a2763cd808da1d…

MALICIOUS

PDF

89.2 KB Created: 2021-07-31 13:48:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 0e0de1f4f4db88cb8f27601611c8b7f3 SHA-1: 662f6893beaf8747b0f35e991b42ad3caf90b566 SHA-256: 57a2763cd808da1dd2d5d15db65c8620bbf6ff024393428abe28b2c2324a8e0d
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a ML classifier and ClamAV, indicating it is likely a phishing or malware distribution lure. It contains numerous links to external websites, many of which are hosted on compromised or disposable domains, suggesting an attempt to direct users to malicious content. The presence of a link farm on compromised WordPress upload storage is a strong indicator of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://bestofbucerias.com/upload/file/65936649289.pdf In PDF document text
    • http://krevue.cz/UserFiles/File/dagolukebodatudera.pdfIn PDF document text
    • https://stopserv.ru/files/file/8561511380.pdfIn PDF document text
    • https://sakkestadbil.no/userfiles/file/didizilafesubarexo.pdfIn PDF document text
    • https://www.lucaslobker.com/minor/ckfinder/userfiles/files/99322479622.pdfIn PDF document text
    • https://aterhesseg.com/up_image/file/44796996735.pdfIn PDF document text
    • http://polskienarty.pl/data/aktualnosci_imgs/file/57381273210.pdfIn PDF document text
    • https://poolpoint.be/uploads/file/zejuju.pdfIn PDF document text
    • https://monacollection.ua/wp-content/plugins/super-forms/uploads/php/files/95777ff1d3d0820e09e323163dc929a0/nopukakemipufogujem.pdfIn PDF document text
    • http://acecaalcoy.com/userfiles/file/7642408132.pdfIn PDF document text
    • http://geose.ru/userfiles/file/18624830879.pdfIn PDF document text
    • https://freedomtampons.com/wp-content/plugins/super-forms/uploads/php/files/33bb538b0c0f9726136217fb999ee7c4/girurilavotu.pdfIn PDF document text
    • https://agrachoff.ru/wp-content/plugins/super-forms/uploads/php/files/2c15afc34ce73d7f7e1ad115a43627da/pujulex.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/essier9a7hfr302b8rroaat03l/7413123610.pdfIn PDF document text
    • http://rebornfair.com/FileData/ckfinder/files/20210608_F07D14DE8745691B.pdfIn PDF document text
    • http://refpecsbelvaros.hu/kepek/files/83655273532.pdfIn PDF document text
    • http://sjar-tech.com/uploadfile/file///2021071303484846.pdfIn PDF document text
    • https://wagaskar.com/media/majikovinumotavosozaj.pdfIn PDF document text
    • https://alexandrapanayotou.com/web/images/static/file/91050975269.pdfIn PDF document text
    • https://www.vbclighting.com/wp-content/plugins/super-forms/uploads/php/files/2fcc0c127944f41189d4b97715be7533/xososazovijuwexisef.pdfIn PDF document text
    • http://aleeblog.com/wp-content/plugins/super-forms/uploads/php/files/fejqutcpgih1mug2uo5de7sgb7/76738142520.pdfIn PDF document text
    • http://gmei.lt/ckfinder/userfiles/files/61732440913.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/9f6ffdf7077fed4bedbfa42d66858e09/kavadij.pdfIn PDF document text
    • https://singaporeroadshow.com/wp-content/plugins/super-forms/uploads/php/files/0a2c9f337918d745bd8959867ac3372e/xununuzewinujoguk.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=how+to+take+apart+a+maytag+gas+dryerPDF 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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f82e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF82E 10776 bytes
SHA-256: 4ebd7a0b8967aba2b63f21dc92da6685e1879059d17bc0e54e66b706e69b02fe
font_01_sfnt_off000110eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110EB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000128fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128FD 17332 bytes
SHA-256: 09df57f6ce0c82eb9840e4c9f6e7232752f360844488dafd4104f218f1c899d2