Malicious PDF — malware analysis report

Static analysis result for SHA-256 6550adacffd9a1ea…

MALICIOUS

PDF

88.4 KB Created: 2021-09-05 11:14:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 34ee6bc0ab1aca0f1258761a3615ff5c SHA-1: 192b8e38da06b5e0f727901ef92c65909848bffc SHA-256: 6550adacffd9a1eaa38d3025fe80b00321bbddde4d5c33da5aa67de8d2fb6cbb
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a link farm with numerous URLs pointing to disposable hosting and compromised CMS upload storage, suggesting an attempt to obscure the final destination and evade detection. The primary purpose appears to be redirecting users to external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 http://yeosingol.com/FileData/ckfinder/files/20210726_AC48395118A35E0A.pdf In PDF document text
    • http://masan315.net/board/imagefile/file/faliluwadobi.pdfIn PDF document text
    • http://animalscipublisher.com/files/upfiles/file/wisireseful.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/18ae71323ea4e35f8168f3e1b3390608/44492778190.pdfIn PDF document text
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c2ad905892---33354232084.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f77440d2b0---56537932338.pdfIn PDF document text
    • http://premium-t.info/files/files/24663134169.pdfIn PDF document text
    • https://prana.video/wp-content/plugins/super-forms/uploads/php/files/eg07l424sj60goblbdbod9jnf2/figukoxitigudakiguzikuges.pdfIn PDF document text
    • https://path.mn/userfiles/files/juzafufavijukigawib.pdfIn PDF document text
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/59d9254ed38d4798abc80f0df8f60597/wegirigawepavugav.pdfIn PDF document text
    • http://stark-tools.ru/images/uploaded/4584214115.pdfIn PDF document text
    • http://secureyun.cn/uploadfile/file///2021090117240086.pdfIn PDF document text
    • http://luluscafeonline.com/uploads/files/46461280983.pdfIn PDF document text
    • http://zuche0551.com/upload/file/tenedifevabipoguzo.pdfIn PDF document text
    • https://takipcisec.com/calisma2/files/uploads/97932878178.pdfIn PDF document text
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/aaa300da0b8b73cfc97af2a95c6a7318/zujidokij.pdfIn PDF document text
    • https://szabobuszrendeles.hu/files/files/fikerupudowago.pdfIn PDF document text
    • http://zulassungsservice4you.de/bilder/file/petumosiwuxexevu.pdfIn PDF document text
    • http://mavelikaradiocese.org/rapha/ckfinder/userfiles/files/tobabukiforefiwizijowuv.pdfIn PDF document text
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16088e9e415712---mevigopebakilolesenasaje.pdfIn PDF document text
    • https://grupahatak.pl/admin/_fck_files/file/ravebimade.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=texture+of+igneous+rocks+in+thin+section+pdfPDF 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_off0000f3cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3CC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010bde.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BDE 17868 bytes
SHA-256: 739901f41402d6942433d18052b15809f9008b75974ae6400b7f30b4cb56ef70
font_02_sfnt_off00013a7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A7D 10948 bytes
SHA-256: 754c312524c48c818605bef2b61ff22b47d325914f137eb2fb94993c5b86151a