Malicious PDF — malware analysis report

Static analysis result for SHA-256 b0093aa6cb9505a1…

MALICIOUS

PDF

83.1 KB Created: 2021-09-10 19:04:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 210e86aaaff50270e3448ebb38204771 SHA-1: 0a0556a6af22a526084ce8d08f2b3561d1de42e0 SHA-256: b0093aa6cb9505a1505376b941aff93ca4ffe8b548b9d7e5cf1cf27bb9f5765c
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It functions as a link farm, containing numerous URLs that point to various websites, some of which are hosted on compromised WordPress upload directories. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/16139b3e9db4d2---fakerofofapaginumubu.pdf In PDF document text
    • http://www.andreapondika.cz/file/burikuruxedizi.pdfIn PDF document text
    • http://niengrangchuyensau.com/upload/contentFile/file/51305240404.pdfIn PDF document text
    • http://hospitalityroyal.com/upload_files/file/didojawogod.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/f4f90f193b8113f32df64985ce9b7531/gipebam.pdfIn PDF document text
    • http://skkl.cn/filespath/files/20210907193019.pdfIn PDF document text
    • http://coachhouse.info/assets/file/37021406444.pdfIn PDF document text
    • http://ros-audit.com/i/up/file/gevebesireviditaru.pdfIn PDF document text
    • http://www.hausman.eu/images/wyswig_images/file/lavibuvesodofaxaf.pdfIn PDF document text
    • http://760_709737661.mildmedia-dev.eu/uploads/userfiles/files/nagolazigaxarimekut.pdfIn PDF document text
    • http://lifeisartfoundation.org/sites/default/files/images/userfiles/file/sujirebun.pdfIn PDF document text
    • http://cinstech-inspect-survey.com/fckeditor_userfiles/file/87619918901.pdfIn PDF document text
    • https://aqua2go.pl/galeria/file/xodidivolal.pdfIn PDF document text
    • http://mertcelikkapi.com/userfiles/file/varurujezowovarunokesapix.pdfIn PDF document text
    • https://360clothing.indicsys.com/home/www360cl/public_html/uploads/images/files/30525127890.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/p7psfr0e0qafvj8iiao29lbpu6/muvarifazizam.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/eae98419e4faec2182d2ff7a6415ed55/65452188491.pdfIn PDF document text
    • https://xn--i1aam8cb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/b942c1924b5199c53a0f6ef6fffbb781/nubinigak.pdfIn PDF document text
    • http://lasermedia.cn/userfiles/file/93217063665.pdfIn PDF document text
    • http://unitez.net/images/newtech/files/89022409839.pdfIn PDF document text
    • http://cutskytools.com/d/files/46716014050.pdfIn PDF document text
    • http://surtek.biz/image/files/20150319_095639.pdfIn PDF document text
    • http://fgsconsulta.com.br/ckfinder/uploads/userfiles/files/butidufegafuv.pdfIn PDF document text
    • http://hangtatmj.com/userfiles/15255141793.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=how+to+unlock+galaxy+s4+without+losing+dataPDF 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_off0000dc8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC8E 19352 bytes
SHA-256: da76b843baa10a56dd63f8d8af8d755d8ccbbe34cd3b666126d1b501646bfd40
font_01_sfnt_off00010d3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D3E 10980 bytes
SHA-256: 45c4adcc88b17794ea4639ce696dd55bc1057c234544159bdfb7c2a52dc88da8
font_02_sfnt_off00012693.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12693 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1