Malicious PDF — malware analysis report

Static analysis result for SHA-256 35ae1625f3623086…

MALICIOUS

PDF

81.0 KB Created: 2021-09-11 11:16:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 41c1b251ad6b596a6986c76b87bff3c3 SHA-1: 6c3677ea18f199f4d9bbf06346388fb36b26d32c SHA-256: 35ae1625f36230866c6559d8db3a850f0949d989816f9db7abeab0f2c2d64867
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified the document as a link farm, with multiple URLs pointing to potentially compromised or disposable hosting, suggesting an attempt to redirect users to malicious content. The presence of numerous PDF links and the use of 'utm_term' parameters in some URLs further support a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://bukvoznaika.ru/ckfinder/userfiles/files/vumevajujugopuvotif.pdf In PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/161314771d4673---lijibis.pdfIn PDF document text
    • http://austria-ex.com/images/blog/file/nugejetudizofebitesudiv.pdfIn PDF document text
    • https://vibangnhadat.com/uploads/files/11559395118.pdfIn PDF document text
    • https://signika.pl/Upload/file/70664223536.pdfIn PDF document text
    • https://leo.tw/upload/ckeditor/files/26326934333.pdfIn PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/5af5a0434bf7314d14ce5573577ff440/diwuxipakiromalore.pdfIn PDF document text
    • http://flapboxes.custompackageboxes.com/userfiles/files/75985544477.pdfIn PDF document text
    • https://edusfera.pl/upload/file/66173498666.pdfIn PDF document text
    • http://webcertain.ca/contentupload/fckeditorUploads/organization_/file/9994411591.pdfIn PDF document text
    • http://we2meeting.com/ckfinder/userfiles/publics/files/33984649015.pdfIn PDF document text
    • http://fusiongrup.ro/userfiles/file/23031548789.pdfIn PDF document text
    • http://rasmesafar.net/basefile/basefiles/28825959281.pdfIn PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16137916b27400---40612955590.pdfIn PDF document text
    • https://pluviaterra.mx/wp-content/plugins/super-forms/uploads/php/files/e6971d2cab778bb58a7ab634f872ab7f/beroroxap.pdfIn PDF document text
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/bb4e44d68029f5bb2b688eda8be67630/33577917773.pdfIn PDF document text
    • https://jphotographyllc.com/userfiles/file/25367095890.pdfIn PDF document text
    • http://residencelesaline.it/userfiles/files/xisalaxatiwugemop.pdfIn PDF document text
    • https://areopag.ru/sites/default/files/uploads/pafop.pdfIn PDF document text
    • https://livredart.com/ckfinder/userfiles/files/77521328743.pdfIn PDF document text
    • https://mollis.rs/files/10948293433.pdfIn PDF document text
    • https://solucionaesp.com/ckfinder/userfiles/files/8658732749.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139b3178051b---sopezer.pdfIn PDF document text
    • http://bienchidan.org/uploads/files/9922930897.pdfIn PDF document text
    • http://architetturaurbanistica.it/userfiles/files/vewigoguviv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=convert+file+to+apk+onlinePDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d82c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD82C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f043.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF043 10372 bytes
SHA-256: e6c63628fec993245a86b9c7885c8037e2df4260a59262e32a1644f6c202831d
font_02_sfnt_off000107dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107DD 18192 bytes
SHA-256: 5264cd9b171ddf5575dd40f24938d256dce0eabde6bee77bb0cc61d6e37b81cf