Malicious PDF — malware analysis report

Static analysis result for SHA-256 f6f111f2f681a365…

MALICIOUS

PDF

70.8 KB Created: 2021-09-17 22:12:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 3795e3efa4474a630d2a460cbd8dcafd SHA-1: 0bed59258337489f59ee868627e66b548552572e SHA-256: f6f111f2f681a3658083e67f7798daab6fd832ce91c7efcf70e806f2780e3a26
156 Risk Score

Malware Insights

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

The ML classifier and ClamAV detection strongly indicate this PDF is malicious. It contains numerous links to external websites, many of which appear to be hosted on compromised CMS platforms or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this. The document body is heavily obfuscated and unreadable, but the overall structure and URL findings point to a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://cructi.ru/uplcv?utm_term=live+stream+player+android+download PDF link annotation
    • https://il-gusto.com/images/file/pazusikobizegugenatisela.pdfIn PDF document text
    • http://28777886.com/Lpf/UPFILE/userfiles/files/97408233682.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/esbchoh1g2rc2ua2dbh649jo7m/mupexile.pdfIn PDF document text
    • http://wonderful-foods.net/userfiles/file/bonetuverunib.pdfIn PDF document text
    • http://forma8.kz/ckfinder/userfiles/files/surumi.pdfIn PDF document text
    • http://friulanamarmi.it/images/file/24322426697.pdfIn PDF document text
    • http://montoaneli.com/ckfinder/files/20738705134.pdfIn PDF document text
    • http://www.atccs3.it/atccs3/fckeditor/editor/ckfinder/userfiles/files/lavonevufuwuxexisar.pdfIn PDF document text
    • http://graciaindoutama.com/kingkong/userfiles/files/51345863975.pdfIn PDF document text
    • http://fuzoku-kyujin.jp/ckfinder/userfiles/files/gilovamoke.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1613012ff23f3e---notesobekopajibivomalas.pdfIn PDF document text
    • https://associazionebriciole.it/public/file/wobilovisevevipojizojite.pdfIn PDF document text
    • http://antonio-pelella.eu/userfiles/files/58707553145.pdfIn PDF document text
    • https://milorem-service.ru/userfiles/file/paridejafa.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/on5667uar8hjrdmgd6rt5qe4pa/31403308181.pdfIn PDF document text
    • http://rootbeadmill.com/upload_fck/file/2021-9-14/20210914032546299719.pdfIn PDF document text
    • http://tpdw.pl/userfiles/file/fowikurosanowotiguwa.pdfIn PDF document text
    • https://infosantiere.ro/userfiles/file/jagoj.pdfIn PDF document text
    • http://sprostredkovanieuverov.sk/res/file/45344647594.pdfIn PDF document text
    • http://secureyun.cn/uploadfile/file///2021090314474942.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e0495be625---17423391963.pdfIn PDF document text
    • http://hnfhdc.com/UpLoadFile/2021091209205633293.pdfIn PDF document text
    • https://bompentax.com/quangbasanpham/app/webroot/upload/image/files/tagez.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_off0000b647.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB647 15224 bytes
SHA-256: 07c68ad1c504a8e3c4a75658b638cf2ab51035a806a874558bb1a5ad661514e4
font_01_sfnt_off0000dca7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCA7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f4be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4BE 10776 bytes
SHA-256: 97f09c5c70ae7d66e4fdeaba13613b63d07e955f5830f137397b753d1587216a