Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8812c1b5482f766…

MALICIOUS

PDF

74.8 KB Created: 2021-09-20 11:59:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 6a001f69af932ee2f573b34c7604b5a9 SHA-1: c9e5a363b1dfb072d635f3ec84a8c0b2f39b4456 SHA-256: f8812c1b5482f7666939dd2fac641d6bb5787adffec9b8280a027ae4b8a5fae9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The presence of external URI links and link farm heuristics supports the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://inwebjor.ru/uplcv?utm_term=camscanner+apk+for+pc+free+download PDF link annotation
    • https://arvikabc.com/images/uploadedimages/file/nebovifanubo.pdfIn PDF document text
    • http://myslizdrave.com/soubory/xerevovalele.pdfIn PDF document text
    • http://dxczx.com/ckfinder/userfiles/files/20210902_065700.pdfIn PDF document text
    • http://labsshop.com/d/files/99924124699.pdfIn PDF document text
    • http://cuuhoatudong.com/upload/files/zaxadukonu.pdfIn PDF document text
    • http://www.pacautomarketing.com/file/wepulunef.pdfIn PDF document text
    • http://ghinelliarchitettura.it/userfiles/files/pitinevalasubupidubeve.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c91a6a107d---49556355756.pdfIn PDF document text
    • http://phutungtdc.com/upload/files/14804803606.pdfIn PDF document text
    • http://weifong.tw/fckimages/file/dazepoxomokodov.pdfIn PDF document text
    • https://giridhareye.org/ckfinder/userfiles/files/10044323826.pdfIn PDF document text
    • https://www.sistemkabin.com/ckfinder/userfiles/files/dibedufiral.pdfIn PDF document text
    • http://meubelenindex.nl/images/uploads/nodukemudunapigekarasofu.pdfIn PDF document text
    • https://paulogomeslda.com/userfiles/file/19379350151.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/c837cd12aeb396867a450c3db97c786a/12959013508.pdfIn PDF document text
    • http://clairvoyantinfotech.com/demo/images/tiseta.pdfIn PDF document text
    • http://www.kowel.com/ckfinder/userfiles/files/1631192622.pdfIn PDF document text
    • https://csn-alliance.com/data/files/laxilekakix.pdfIn PDF document text
    • https://solarconsulting.org/wp-content/plugins/super-forms/uploads/php/files/9b93b67cabca8a05ca023fd9ed52696c/1175519828.pdfIn PDF document text
    • http://wronba.com/uploads/wysiwyg/file/48006311284.pdfIn PDF document text
    • http://anbao.vn/uploads/userfiles/file/11237805160.pdfIn PDF document text
    • http://phonphangschool.com/upload/files/towakipiliboda.pdfIn PDF document text
    • http://taikenplan.jp/ckfinder/userfiles/files/miriretixege.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_off0000b9e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9E7 10800 bytes
SHA-256: d5dd98338cdda2a4390df4db2cbc4490870d8b40a045d482580d31479ba18f8a
font_01_sfnt_off0000d2d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2D5 19164 bytes
SHA-256: cd37c451f4728103d1ee4569d7395738f476b91e8b4c182c210685738129877e
font_02_sfnt_off0001040f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1040F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1