Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd90cdefd0230ca1…

MALICIOUS

PDF

83.0 KB Created: 2021-09-21 12:36:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6303406c3bb48c4d0bcff8c10a739bf9 SHA-1: 255877a82a8d909c6caf89731c115014a18af990 SHA-256: cd90cdefd0230ca10dd5d3daa2d8b19c1a12154a083c419c6dd6498eebbbb722
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a PDF link farm, with numerous URLs pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or SEO manipulation scheme. The embedded URLs are likely used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://synerhu.ru/uplcv?utm_term=free+android+camera+apps+download PDF link annotation
    • http://seoaudytor.pl/userfiles/file/73479964995.pdfIn PDF document text
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/c46726c74fea1df04b752b6f36d7ba09/72694356726.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/qvjkitu5eneaalh4luo7j9u9ue/danubew.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///22404666629.pdfIn PDF document text
    • http://smolensk-bakaleya.ru/userfiles/file/pipovuzobakan.pdfIn PDF document text
    • https://propiedades.net/ckfinder/userfiles/files/tejadokefonatomotal.pdfIn PDF document text
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613513adb8bad---nuvarisexelotumubegizev.pdfIn PDF document text
    • http://asacnfservices.com/ckfinder/userfiles/files/tenukebeniwaxati.pdfIn PDF document text
    • https://autopsrus.aerovents.com/ckfinder/userfiles/files/kanefexerunujew.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16133dec0120eb---33106197488.pdfIn PDF document text
    • http://bandenplaats.nl/cmsimages/file/dajev.pdfIn PDF document text
    • https://attackworkoutprogram.com/app/webroot/files/ckfinder/userfiles/files/85485844932.pdfIn PDF document text
    • http://didula.com/img/file/59076517126.pdfIn PDF document text
    • http://robertfeinberglaw.com/images/edit_images/file/70886204399.pdfIn PDF document text
    • http://zjqzzx.com/uploadfile/file/2021091103553073499.pdfIn PDF document text
    • https://onecre.com/images/content/files/fojileguweduxitos.pdfIn PDF document text
    • http://ndfeef.com/radiant/mechimobiles/userfiles/files/4189860092.pdfIn PDF document text
    • http://domingo.hu/ckfinder/userfiles/files/296745861.pdfIn PDF document text
    • https://yunglin.com/uploadpic/files/80763952372.pdfIn PDF document text
    • https://binarbaidfabrication.com/public_html/userfiles/file/verorugepezijal.pdfIn PDF document text
    • https://bestcoloringpages.com/userfiles/file/18361351746.pdfIn PDF document text
    • http://pate4me.com/userfiles/file/60293068951.pdfIn PDF document text
    • http://www.hangmandigital.com/files/file/1955019006.pdfIn PDF document text
    • http://ledlight-lamp.com/mingyi/images/userfiles/file/jores.pdfIn PDF document text
    • http://www.libroparlatolions.it/backoffice/ckfinder/userfiles/files/74929345260.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_off0000e099.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE099 10640 bytes
SHA-256: b93c50106c579dbbe90a2d76999e570542e49c9cc2f16696f49f9725a984c04a
font_01_sfnt_off0000f8e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8E5 17256 bytes
SHA-256: b709ed716cb72d49e752eebd99189a916841a8fb75e3b5a91220f18df3a53010
font_02_sfnt_off000125c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125C4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1