Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b8b15193521dc5d…

MALICIOUS

PDF

72.0 KB Created: 2021-09-28 04:38:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 37314abbe9239e18cadb52c6e8235005 SHA-1: 7d366096788e309ca7fb10d039ac66bf148b1f8e SHA-256: 8b8b15193521dc5d9e7b7ee8b0b7b965048410e35772f65d9295cbec2f9feaf5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be compromised or disposable hosting. Heuristics indicate it's a link farm and potentially a phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9893

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=mp3+to+video+converter+free+download PDF link annotation
    • http://sendedianqi.com/upload_fck/file/2021-9-17/20210917232823166497.pdfIn PDF document text
    • https://e-uchebnici.com/img/file/nuwivobepeputawafokubidek.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613c26427ccc6---wokazilewatodavip.pdfIn PDF document text
    • http://twgo8.com/uploads/base/files/202109050327458274.pdfIn PDF document text
    • http://jeanthompson.nl/ckfinder/userfiles/files/fotuwukovev.pdfIn PDF document text
    • http://studiopol.com/userfiles/files/gotibatiduvavirap.pdfIn PDF document text
    • https://poojaindiangrill.com/nbloom/fckuploads/file/80970608833.pdfIn PDF document text
    • http://apple888.vn/luutru/files/kebibalazatogabuzaluvez.pdfIn PDF document text
    • http://ageddfjtjgrade.pretty-match.com/upload/files/lefisolukalunebunabakir.pdfIn PDF document text
    • http://olsztyntransportmedyczny.pl/userfiles/file/goganora.pdfIn PDF document text
    • https://markiza-trade.ru/admin/ckfinder/userfiles/files/62982143722.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614caac15798e---6124796028.pdfIn PDF document text
    • https://theptaynam.vn/upload/files/86543857263.pdfIn PDF document text
    • https://clifestyle.net/uploades/userfiles/file/jisupuwudivi.pdfIn PDF document text
    • https://annekienlen.fr/imagesfile/47428371850.pdfIn PDF document text
    • https://people11people.com/uploads/File/79783421199.pdfIn PDF document text
    • https://sportnazona.bg/f/uploads/files/defesukobaxemolewe.pdfIn PDF document text
    • https://agrocare.ro/ckfinder/userfiles/files/tagoxux.pdfIn PDF document text
    • http://wpklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/nixenuralafe.pdfIn PDF document text
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/571caf33a6b8fea5a15c5d088c76afd5/24624475578.pdfIn PDF document text
    • http://pure-chiral.com/upload/files/lodajalodevojerakekirurin.pdfIn PDF document text
    • http://geasit.it/userfiles/files/rerebazisunabeworumipid.pdfIn PDF document text
    • http://elliptical-trainers.ru/ckfinder/userfiles/files/81938937367.pdfIn PDF document text
    • https://vaitinhdien.com/app/webroot/upload/files/96937074994.pdfIn PDF document text
    • http://studioriboldi.eu/userfiles/files/kidavupupogilogefe.pdfIn PDF document text
    • http://greenhere.cn/upload/ckimg/files/202109031554228158.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_off0000b588.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB588 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cd9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD9F 10764 bytes
SHA-256: e8641a137a9c95ed21e699218ad59c1574057a1bee5d3125963012d5e045dadf
font_02_sfnt_off0000e691.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE691 17356 bytes
SHA-256: acd28a6d387d0f5f42cbe3166acc4749c9db3ba0bc25d210f93139ae618ca917