Malicious PDF — malware analysis report

Static analysis result for SHA-256 855425714ef028c7…

MALICIOUS

PDF

87.7 KB Created: 2021-07-09 18:02:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: a89616fb7deb8a5f8dc5fd1ef958b99f SHA-1: 4129789dda58c52f440e6b3d6b19a1aac8fafb4f SHA-256: 855425714ef028c7b35d4b0fd44d5ad6b9f38ea4432349b956ed3950088a3cc1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised WordPress sites, suggesting it functions as a link farm to distribute malicious content or phish users. The presence of embedded URLs and the nature of the heuristics strongly suggest it is used for initial access via spearphishing, likely leading to further stages of infection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://crewmak.ru/uplcv?utm_term=culture+in+second+language+teaching+and+learning+pdf PDF link annotation
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a65e1e8e09a.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/16081829d06a0b---5055516171.pdfIn PDF document text
    • http://vidol.nl/userfiles/file/46294463194.pdfIn PDF document text
    • https://www.explosivo.gr/wp-content/plugins/super-forms/uploads/php/files/e580fb3f022617a19e57d4590fb15d5c/zugirafawezapi.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160856b9263a36---47272562462.pdfIn PDF document text
    • https://janeunchained.com/wp-content/plugins/super-forms/uploads/php/files/oogutekktcec2onsjn6at084u3/13175365962.pdfIn PDF document text
    • http://insureacompany.com/userfiles/file/fozetedukakemozowupemore.pdfIn PDF document text
    • http://summithigh49.com/clients/3/33/3334069ac8a672cbece4a9536eb221cc/File/33434118734.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607d2ed49eacd---97587745081.pdfIn PDF document text
    • http://mgtofubbq.com/uploads/files/51988626123.pdfIn PDF document text
    • http://ypperfect.com/ckfinder/userfiles/files/ronozaxoxuxosogesot.pdfIn PDF document text
    • https://sygimportaciones.com/wp-content/plugins/super-forms/uploads/php/files/pquf6eochtpiqudejbh2n7f37a/87701919164.pdfIn PDF document text
    • https://bikinibody.be/wp-content/plugins/super-forms/uploads/php/files/ffdcnblm9ene2vuacdp14qqhhi/zivolifogivedewefik.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e1fd25119c3---nuratanuzotuvixogodetu.pdfIn PDF document text
    • https://arnetbilgisayar.com/upload/ckfinder/files/lisolofilufopezirazug.pdfIn PDF document text
    • http://bigandtallking.com/userfiles/file/1353219273.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/5aa735872d735db81309f577818ceef7/jatomise.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/e4839d61247810824e3a6ee76e405dea/vujisujup.pdfIn PDF document text
    • http://architettoseneca.com/userfiles/files/30412566001.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/1608166c809ec0---55780082287.pdfIn PDF document text
    • https://bibliothequedesarts.ch/ckfinder/userfiles/files/6292357060.pdfIn PDF document text
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c6875f2c1a---61961923136.pdfIn PDF document text
    • http://shmountaineering.co.uk/wp-content/plugins/super-forms/uploads/php/files/ent5ekeeiatj8krl6353fjcbk7/mawuferoketodud.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e46718fb7d---sozibijepijitadaku.pdfIn PDF document text
    • https://albawadiroad.com/userfiles/files/3843207562.pdfIn PDF document text
    • https://asi-filter.pl/files/file/damipimel.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_off0000f3d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3D4 11028 bytes
SHA-256: c4ba1ec45b3394a110e6b5966ad01bba0f85b8c1adccc62bfa7fc194c922a13f
font_01_sfnt_off00010d3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D3A 16956 bytes
SHA-256: 10cb06f687c5f582e6956c4eaa665cbb2e9ea2fc2cd63bf52088190a2cdb308f
font_02_sfnt_off000138fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x138FD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1