Malicious PDF — malware analysis report

Static analysis result for SHA-256 753f550e5504e58b…

MALICIOUS

PDF

73.4 KB Created: 2021-09-26 00:53:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 6bc39c929754c5a9573e0a064afa3a3f SHA-1: 152dc5e6a42b987adfc8ba2dbcae8fdc28765dff SHA-256: 753f550e5504e58b0a2a6f088e2d556874f4d022de3f69f1391c183bbb8621eb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous external links, many of which point to disposable hosting or compromised CMS uploads, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://synerhu.ru/uplcv?utm_term=tamil+mobile+movies+free+download+2019 PDF link annotation
    • http://sichera.eu/userfiles/files/71631924504.pdfIn PDF document text
    • https://xn--pssa17sw71b.tw/upimages/files/503603906.pdfIn PDF document text
    • http://9262895.ru/ckfinder/userfiles/files/10337516856.pdfIn PDF document text
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/968d9a8ead582b4a052bfb134c9adce7/sulimixozeku.pdfIn PDF document text
    • https://beautydent.hu/editor_up/lekaverewaji.pdfIn PDF document text
    • http://ybshajiang.com/userfiles/file/2021-09-13/210913235043987787vzgpofhdledu.pdfIn PDF document text
    • http://luckdidea.com/ckfinder/images_store/files/10414888179.pdfIn PDF document text
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/521de23a45b1a1fcd08d6fb830dc5c01/gaziwelolef.pdfIn PDF document text
    • http://scuolascifondocortinadolomiti.it/userfiles/files/1843610829.pdfIn PDF document text
    • https://semangkabiji.com/contents/files/karopepotijowixajojofereb.pdfIn PDF document text
    • http://tverzhilservis.ru/foktver.ru/ckfinder/userfiles/files/89399549637.pdfIn PDF document text
    • http://claudiamelchior.it/images/file/penadolebodota.pdfIn PDF document text
    • https://wronba.pl/uploads/wysiwyg/file/towopadokof.pdfIn PDF document text
    • http://parzenica-bialka.pl/userfiles/files/85457416753.pdfIn PDF document text
    • https://karolinanowak.com/userfiles/file/18300958468.pdfIn PDF document text
    • https://ms2oke.com/contents/files/rubapidineman.pdfIn PDF document text
    • http://magendans.com/imagefiles/file/domul.pdfIn PDF document text
    • http://diamantina-joaillerie.com/ckfinder/userfiles/files/nupemad.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/161313ef7b65fc---83703074787.pdfIn PDF document text
    • https://propertiproperty.com/Uploads/userfiles/files/bunopiwadabemegu.pdfIn PDF document text
    • http://okfilm.kr/userData/board/file/70646260590.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fd17d7ac49---fekasolexegedonij.pdfIn PDF document text
    • http://neuroxl.com/images/file/6196966500.pdfIn PDF document text
    • http://nutrizionisti.eu/public/thread/risorse/file/53707856855.pdfIn PDF document text
    • http://datcat.vn/2018/file/7266186272.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_off0000b85e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB85E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d075.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD075 11132 bytes
SHA-256: 8315d9dc097f3f3120ad23a068d434808f51e51ed3aa62a78e4ba118368116a5
font_02_sfnt_off0000ea87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA87 17428 bytes
SHA-256: 96052a0477dd2538165d1fe6da16e0a10988be124680d9a7add11a8f7a7a0c15