Malicious PDF — malware analysis report

Static analysis result for SHA-256 550eb9773794de28…

MALICIOUS

PDF

78.3 KB Created: 2021-09-16 19:00:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 8e056450cb0a658ddfbd1ced87eb0dd1 SHA-1: af9b8eb2d5fc6e30ee2da2512804ebc33855db6f SHA-256: 550eb9773794de284f990dc65398fae7c41797dac86dc97d172857d0aab2cd0b
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to compromised CMS uploads or disposable hosting domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of multiple PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 https://allytemp.ru/uplcv?utm_term=the+walking+dead+season+10+episode+19+watch+online+free PDF link annotation
    • http://carzip.biz/files/uploads/files/remazowofidije.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/hpkk4baroror3rgnd0mbeej0ga/29154974245.pdfIn PDF document text
    • https://sysyanginguvenlik.com/uploads/files/wuvexebenujuma.pdfIn PDF document text
    • http://cbstav.cz/file/60064413947.pdfIn PDF document text
    • http://biomehl.com/images/content/files/85736171449.pdfIn PDF document text
    • https://www.tocbirsen.org.tr/ckfinder/userfiles/files/23626697391.pdfIn PDF document text
    • http://droprint.my/home/ququ4923/public_html/userfiles/file/51203488425.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130fd0f7183e---zozuk.pdfIn PDF document text
    • http://moderncarrent.com/user_img/files/85815000632.pdfIn PDF document text
    • https://rentcar888.com/uploads/files/202109061400224166.pdfIn PDF document text
    • http://leeclinic.kr/userData/board/file/3702810235.pdfIn PDF document text
    • http://contelex.it/userfiles/files/95292390725.pdfIn PDF document text
    • http://www.moyekolodin.com/files/virafemaxar.pdfIn PDF document text
    • http://bouwbedrijfansing.nl/userfiles/file/12465134586.pdfIn PDF document text
    • http://tantex.org/tantex/tantexuserfiles/file/57758144329.pdfIn PDF document text
    • https://promptcorporate.com/ckeditor/ckfinder/userfiles/files/rufal.pdfIn PDF document text
    • http://svadbavmoskve.com/content/xuploadimages/file/jadozowimowezi.pdfIn PDF document text
    • http://morakothotel.com/file_media/file_image/file/7344683054.pdfIn PDF document text
    • http://huucodatlanh.com/userfiles/file/20598547806.pdfIn PDF document text
    • http://poptheme.cn/uploadfile/files/20210908_212503.pdfIn PDF document text
    • http://quangcaosms.org/media/ftp/file/65247799447.pdfIn PDF document text
    • https://segurosjdd.com/wp-content/plugins/super-forms/uploads/php/files/smj3urhge7u9iflg5mupu23q23/penelegawosudesixosa.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_off0000cb7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB7A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e391.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE391 11380 bytes
SHA-256: 4d33368313c63ae339beedf23d3e92ef72f1c22a66a01f57a9136960843641b7
font_02_sfnt_off0000fe32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE32 17392 bytes
SHA-256: 9e8b1c3b840ac5d2e89ebaee43a09abaad80fdd9987bb4062d7778343f8b06e9