Malicious PDF — malware analysis report

Static analysis result for SHA-256 a792d694ba0218d6…

MALICIOUS

PDF

89.5 KB Created: 2021-06-28 04:28:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: c23b87b376ff5e8f85f0932b29ad5489 SHA-1: f8a993a1f4726cc8c8e8aae77abc7c3f205e3192 SHA-256: a792d694ba0218d6a890f47a76f125b7e334dc38bc59827fe5db445847727b51
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1190 Exploit Public-Facing Application

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Several heuristics point to the use of a link farm hosted on a compromised WordPress site, suggesting it's used to distribute further malicious content. The presence of numerous unknown URLs hosted on various domains, many of which appear to be compromised CMS uploads, reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9822

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 http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/160a1df313fbdf---lifelevomesitolije.pdf In PDF document text
    • https://swift-tw.com/lcc/upload/files/sawozezonasix.pdfIn PDF document text
    • http://vervesimuhub.com/userfiles/file/kanuditapuxu.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/mujupulurozovupugarawu.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607b204572d6d---bozipurumi.pdfIn PDF document text
    • http://www.anieliasfx.com/uploads/textareas/file/wigawezerazukiku.pdfIn PDF document text
    • http://zawayakw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac2daa5292e---kowezidutis.pdfIn PDF document text
    • https://forcechicago.com/wp-content/plugins/super-forms/uploads/php/files/066fecde0b418ab3acab0b5d969b3346/junevatilagafizumigukax.pdfIn PDF document text
    • https://chpcentre.com/files/file/nefurebaroj.pdfIn PDF document text
    • https://emmaushuis.org/pages/23800176138.pdfIn PDF document text
    • http://mmckno2010.zkosuchdol.info/files/96706973635.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/7d365625a7dfc7dcf65c2ecdafdd3675/gejamugeruduv.pdfIn PDF document text
    • https://xn----9sbccjdbca7cyaieg1a3j.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/378129a29ebf91d0cbb52b4357922cfa/kizafuvo.pdfIn PDF document text
    • http://mayfamilycircle.com/clients/5/53/53cd9f4101e72b768929e5daf979c2da/File/46666164330.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/pogafewodesotodixudesesu.pdfIn PDF document text
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/88d64b3ae4b70888666c447878273beb/49965319188.pdfIn PDF document text
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/160bfc1efb8361---sedosagerudamexonagega.pdfIn PDF document text
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/160bf58aa48189---31552754279.pdfIn PDF document text
    • http://asijskepotraviny.cz/files/file/lakijowebor.pdfIn PDF document text
    • http://plenaadoracao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607f7013699a7---wanalef.pdfIn PDF document text
    • https://nikken-engineer.jp/export/sd205/www/jp/r/e/gmoserver/8/6/sd0748886/nikken-engineer.jp/fckeditor/upload/file/60561127986.pdfIn PDF document text
    • https://europartner2.pl/uploads/68025645142.pdfIn PDF document text
    • https://carparts-fixture.com/file/file/35576410711.pdfIn PDF document text
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d6056e60f0---pimuzotije.pdfIn PDF document text
    • https://daluxerealty.com/wp-content/plugins/super-forms/uploads/php/files/r6btg18njvpv85ai9rpi6g6ae0/4163897007.pdfIn PDF document text
    • http://www.lifestaralberta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2991d70b11---gojigol.pdfIn PDF document text
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/u7dkgrahgafa1cg824bqjs2eld/menamenuwafeze.pdfIn PDF document text
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/33c64b61ecb0f03daae2886b7ea0508c/dalifilamoxivugujaxogenup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=construction+expenditure+calculatorPDF 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_off0000fa5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA5F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011271.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11271 17280 bytes
SHA-256: 6f9acc795701985debb1712334ac24a36cf27075cb2c7a5f1f2e3edea70e42bd
font_02_sfnt_off00013fb2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13FB2 10740 bytes
SHA-256: d2baa41db100d4c51f5ee3c0d7bbd1307b76f6286bdd905bc85af09de6b2c6e7