Malicious PDF — malware analysis report

Static analysis result for SHA-256 8dc998ab74751f6a…

MALICIOUS

PDF

81.2 KB Created: 2021-09-22 18:55:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 5538e6f2ad0a500537d0d7ce659fd3d2 SHA-1: ad9d0bc3a3b274144f5ef75dfc811bc5ee2e5340 SHA-256: 8dc998ab74751f6a9a87daa6f73d5032472f55a9368b5447a244b139bf736fba
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users to malicious sites. The document body is unreadable, but the heuristic firings strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://qamsar.org/userfiles/files/58297458866.pdf In PDF document text
    • http://moskvaznaet.ru/upload/files/78882029738.pdfIn PDF document text
    • http://alles-vom-schreiner.de/userfiles/file/17777050223.pdfIn PDF document text
    • http://hyundaihungthinh.com/uploads/images/files/41953764083.pdfIn PDF document text
    • http://obchodsezlatem.cz/upload/files/4382412767.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ff52f6de48---zegibiduwavotisino.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130d304267ab---losif.pdfIn PDF document text
    • http://beiwendq.com/data/attachment/file/87348772671.pdfIn PDF document text
    • https://gamepinleri.com/calisma2/files/uploads/42800271769.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161429fc1b4319---monafapekawodonedovinenib.pdfIn PDF document text
    • http://geometrabottero.it/userfiles/files/gafixomakokolixaxitumi.pdfIn PDF document text
    • http://htbestcomputer.com/media/ftp/file/dajamadivusuno.pdfIn PDF document text
    • http://3t-t.com/User_File/UpFile/file/20210916135503_bGVidWJ1d2F0ZXNvd2VuZWdpcmVsb3hp.pdfIn PDF document text
    • http://area100impianti.it/userfiles/files/67257549908.pdfIn PDF document text
    • https://www.speeddating.lt/speeddating/ckfinder/userfiles/files/46220820480.pdfIn PDF document text
    • http://timebank.ru/sites/default/files/photos/pagefile/bifuvalada.pdfIn PDF document text
    • http://suaups.net/userfiles/file/9978145202.pdfIn PDF document text
    • http://nakamurasangyou.jp/app/webroot/uploads/files/mudutanirutizewobi.pdfIn PDF document text
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/584a9abf140d3cb730df8750bddcee91/92069430735.pdfIn PDF document text
    • https://tourpon.kr/FileData/ckfinder/files/20210921_2417CC7F68DA1640.pdfIn PDF document text
    • https://resulgame.com/calisma2/files/uploads/48130412744.pdfIn PDF document text
    • http://szintai.hu/ckfinder/userfiles/files/vuniwaduxit.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=bill+mckibben+the+end+of+nature+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_off0000d7a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7A4 11104 bytes
SHA-256: 071786d039f0d13af722a75529732439cee290748c85f93a1f56399e79d19871
font_01_sfnt_off0000f115.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF115 17572 bytes
SHA-256: 8bdd03057f006f151a38ea3e97bb1141e2e00f4a6085ba5a58511aa9c5e20fdf
font_02_sfnt_off00011f00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F00 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1