Malicious PDF — malware analysis report

Static analysis result for SHA-256 8cdc5110b4e2e505…

MALICIOUS

PDF

84.4 KB Created: 2021-09-01 13:22:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fcac450d5df872f32d0bf576e32da1c3 SHA-1: c7d07354205e80c2d110c61154e53c844015c1c7 SHA-256: 8cdc5110b4e2e505f58591ef93cb396bcb0e4a65eab6ccc7a90e6bbed0988324
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous embedded links, many pointing to compromised CMS upload directories and disposable hosting, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the heuristic firings and URL patterns are sufficient to infer a malicious link-farming attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9983

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://astek-telem.fr/userfiles/file/91236941831.pdf
    • http://proxima-design.cz/files/file/diwugakesuleza.pdf
    • http://ilkemymm.com/image/files/katekusafutuk.pdf
    • http://jinistudy.com/_UploadFile/Images/file/pasawodipaka.pdf
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/tbr2h817v8cdnq6na1p9jkvqg6/50569311669.pdf
    • http://actlogistic.vn/upload/editor/files/weferenazapidivutorudup.pdf
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075ccc1db4a4---vatelejefun.pdf
    • https://huangs.tw/uploads/files/202108310055195071.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/j2avsts61fk46ggrc378q7p131/melipezuv.pdf
    • https://twfern.org/upload/ckfinder_temp/files/20210527171033.pdf
    • https://yennenga.org/business_school/uploads/file/44188476532.pdf
    • http://aliceinformaticasrl.com/user/pages/73850916926.pdf
    • http://palakkadtourism.in/ckfinder/userfiles/files/68703871256.pdf
    • http://eventcompany.org/clients/e/e3/e30ef11cf4efe639fe6592aa37b9cb94/File/lobaduka.pdf
    • http://mopron.ru/upload/files/bebakuwejiwudaxebit.pdf
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612847a4dafc7---wutifenojigenun.pdf
    • https://dewalt-naradi.cz/media/upload/editor/file/11839113407.pdf
    • http://atsrealtyvietnam.com/upload/files/penasozepigoxon.pdf
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/edc0003b8ea1756b851f67ed6a01a156/kefekosaxewipizi.pdf
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/1606e1e326f885---mexusasanugevovaz.pdf
    • https://nakipoglugroup.com/upload/ckfinder/files/68112217688.pdf
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a80aefc4c5d---minimi.pdf
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/16fso9qgmks592i17ghr5904a6/79401076548.pdf
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bc9d745e9e3---nakokox.pdf
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/36db51aa525cf81743d89a5f18a6bb5d/zepunoselubowotonoganop.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=lords+mobile+monster+hunt+gryphon
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e1d7.bin
717ac6f9e28b955b6450ed9cbc51eda8c24dbb321b7a8029b4d260d986f81aa4
pdf-font-stream PDF embedded font (sfnt) at offset 0xE1D7 18564 bytes
font_01_sfnt_off00011229.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11229 16792 bytes
font_02_sfnt_off00012a40.bin
117fe25e49a05196b569775918220a2df5425a22daa6cf10497d8e114918717f
pdf-font-stream PDF embedded font (sfnt) at offset 0x12A40 10988 bytes