Malicious PDF — malware analysis report

Static analysis result for SHA-256 502f710ea0e70c33…

MALICIOUS

PDF

77.6 KB Created: 2021-09-12 07:26:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c4cd87f2257b51c614182b4b1cae410e SHA-1: a51300098c9718ec998c8f41110a85a58bed61ff SHA-256: 502f710ea0e70c336cff2c06687508537737449082a8b4ba053542c1cf20c78d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised CMS uploads and disposable hosting, suggesting a link farm designed to redirect users. The presence of embedded URLs and the nature of the heuristics strongly suggest this PDF is used as a lure, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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=video+to+live+wallpaper+app
    • http://mecateengenharia.com.br/ckfinder/userfiles/files/veribijadirif.pdf
    • http://augustaelectricalwork.com/editorData/file/5786314729.pdf
    • http://savitapiti.org/ckfinder/userfiles/files/26344237796.pdf
    • http://busangh.com/attfile/fckimg/file///202109044851_239730008.pdf
    • http://studiobardinisrl.com/userfiles/files/jebugotuwosutimerufijuf.pdf
    • https://lbjgold.in/ckfinder/userfiles/files/31282718796.pdf
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/26b991188d018853608f407b9594032c/11159871524.pdf
    • http://poliinc.com/upload/files/10493220263.pdf
    • http://www.afamaresme.org/wp-content/plugins/formcraft/file-upload/server/content/files/161309290eb305---25482530462.pdf
    • http://soojuspilt.ee/files/file/36193999472.pdf
    • https://keralatemples.info/ckfinder/userfiles/files/guwet.pdf
    • https://stop-remont.ru/ckfinder/userfiles/files/99630242543.pdf
    • http://seosanhrd.com/userfiles/file/66537712403.pdf
    • http://website-design-company.in/dev3/damodar/ckfinder/core/connector/php/userfiles/files/virarofuxemev.pdf
    • https://zd-zeta.com/uploads/files/202109061354305096.pdf
    • https://saintarseny.ca/sites/saintarseny.ca/files/file/48604681205.pdf
    • http://dreamscar.eu/userfiles/file/67750956026.pdf
    • http://mos-craciun-inchiriere.ro/fckfiles/file/53206274452.pdf
    • https://telliogluhukuk.com/userfiles/file/vebonejebibopiluwe.pdf
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/16131519caa192---17869873404.pdf
    • http://merrygoldholidays.com/ckfinder/userfiles/files/70829299655.pdf
    • https://fetogram.com/images/upload/files/sukafodubodesasategoli.pdf
    • http://lovelyspa.net/ckfinder/userfiles/files/fafidowasijufirepe.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c79b.bin
e8a106ba766734ac3356efbf1d8186a26b211b4913f9256cb197c89875a533a3
pdf-font-stream PDF embedded font (sfnt) at offset 0xC79B 10236 bytes
font_01_sfnt_off0000deb9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDEB9 16792 bytes
font_02_sfnt_off0000f6cb.bin
71868ce25058b31fbc01205bc724219e1b74a9d41a3b1de0df284da560199451
pdf-font-stream PDF embedded font (sfnt) at offset 0xF6CB 19216 bytes