Malicious PDF — malware analysis report

Static analysis result for SHA-256 6319d3e0ef2afcbf…

MALICIOUS

PDF

91.4 KB Created: 2021-09-21 09:52:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 52426f97b5ba5165f4e96ad53e12a36b SHA-1: ae60ee7c6efefed2255a8d4239775387e3ab0bde SHA-256: 6319d3e0ef2afcbf9486a274beff335e67e5719148a49a0248129a41bf1fbbff
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. Heuristic analysis revealed it functions as a link farm, directing users to multiple potentially compromised websites. The presence of numerous unknown URLs suggests a phishing or SEO poisoning campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9726

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 http://salondebellezaanamariaromero.es/ckfinder/userfiles/files/1490083299.pdf In PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145c782ced81---16738444376.pdfIn PDF document text
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/161418cf3123ed---36496629328.pdfIn PDF document text
    • https://penzion-palice.cz/content/28709963491.pdfIn PDF document text
    • https://proia.bg/userfiles/file/3247361336.pdfIn PDF document text
    • http://bibliotekaszamocin.pl/img/upload/files/1538386416.pdfIn PDF document text
    • http://irpuyesh.com/cache/fck_files/file/91922530036.pdfIn PDF document text
    • http://gasasosong.com/upload/fckeditor/file/wosukuvaxizener.pdfIn PDF document text
    • https://vinaarc.com/app/webroot/files/ckfinder/userfiles/files/68883027903.pdfIn PDF document text
    • http://lagerunda.it/public/upload/file/sexojidifuji.pdfIn PDF document text
    • http://dichvuhieuchuan.com/upload/files/200507005.pdfIn PDF document text
    • http://ecohort.com/userfiles/files/90338780096.pdfIn PDF document text
    • http://rancholasmonturaspremios.com/campannas/file/tijapowotuzububaxaji.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/xokivegowesuwanobawu.pdfIn PDF document text
    • https://mytalk7.com/_UploadFile/Images/file/vagewofufizitejizuz.pdfIn PDF document text
    • http://0228339500.kad.tw/kads/ckfinder/userfiles/files/84294583217.pdfIn PDF document text
    • http://gamebonda.com/ckupload/files/26275293186.pdfIn PDF document text
    • https://kominove-centrum.cz/media/files/file/zisokamewumifefepotojejez.pdfIn PDF document text
    • http://posicert.com/upload_fck/file/2021-9-11/20210911182337106697.pdfIn PDF document text
    • http://handbook.hu/upload/page/file/15983980355.pdfIn PDF document text
    • http://szolnokepul.hu/userfiles/file/vuzigonexobe.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f1ddceb4df---75313220200.pdfIn PDF document text
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/kci8r29q52c02ib7va9nmlbrrr/naninibuduji.pdfIn PDF document text
    • http://nwhouse.ru/uploads/file/xugafomewave.pdfIn PDF document text
    • https://prestinireedcorp.com/userfiles/files/42468683356.pdfIn PDF document text
    • https://artistprasanna.com/userfiles/file/judofeveg.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=galaxy+note+4+latest+android+versionPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ef47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF47 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010754.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10754 3892 bytes
SHA-256: 1e4451e83b6f52f572d031d1b19e20c79940e51bfa82678b6f73e3b6cd6954e1
font_02_sfnt_off00011647.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11647 18480 bytes
SHA-256: 9fba8e8b756a61160e63ffba49e8f5dc03f34e9274191679bdb95eb5fbcb08fa
font_03_sfnt_off00014667.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14667 10640 bytes
SHA-256: e7d5a2f94c649c9ab4c7cf2b7154a2f89c15181c965e9560cb47a90aaa019fcf