Malicious PDF — malware analysis report

Static analysis result for SHA-256 6b4a9393950cf47b…

MALICIOUS

PDF

77.0 KB Created: 2021-09-17 06:34:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 078c8dfca1495f847853592abca4317c SHA-1: 27e172d774a7a8733516ec4c34249fcacd223e3f SHA-256: 6b4a9393950cf47bc43f615cc8c74cc1444c7c4234c57a712638c5394363a0e1
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, 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 external URIs and link farm heuristics confirms the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://archism.ru/uplcv?utm_term=tubidy+music+and+video+downloader
    • http://df-2.de/images/daten/file/jotetojekibefevefel.pdf
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/a3fhdfd6nmtm2pvta8a9ch60fk/gomugufudide.pdf
    • http://www.mostenpo.jp/userfiles/files/39886877207.pdf
    • http://sxsasa.org/images_fck/file/1630853669.pdf
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c97ac4cc09---17934311364.pdf
    • https://calendarsunrooms.com/userfiles/files/47691181321.pdf
    • https://pensiunea-escape.ro/ckfinder/userfiles/files/38178775283.pdf
    • https://tsegypt.com/file/dafigodegirepiwavawukipa.pdf
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/b87r1s9djkbevusrlqrpn0vam2/20817879583.pdf
    • http://nextlab-semi.com/files/fckeditor/file/47354689119.pdf
    • http://adamlegal.com/userfiles/file/98318674461.pdf
    • http://hpworld.hu/data/pic/Image/file/xinogeruvurefaror.pdf
    • http://www.lnk-creation.fr/upload/file/29766829488.pdf
    • http://gelikonline.ru/content/Files/50716049682.pdf
    • http://donghobaoan.com/uploads/files/wakozafiwo.pdf
    • https://mosaicopeoplecorporation.com/ckfinder/userfiles/files/9924149695.pdf
    • http://hopkim.vn/upload/files/loniwogez.pdf
    • https://ph2020.org/ckfinder/userfiles/files/tokuwedepileb.pdf
    • https://groupburuemas2.com/contents/files/55735579599.pdf
    • http://1000projects.ru/upload_picture/file/tunupaken.pdf
    • http://jinsonmetal.com/Upload/file/mozesunazexevosaseb.pdf
    • http://apexnepaltravel.com/userfiles/file/99479224068.pdf
    • http://snieznik.pl/userfiles/file/57688817746.pdf
    • https://abisspaandboutique.com/nbloom/fckuploads/file/bufakujejajanerujolatib.pdf
    • http://www.gamylai.vn/uploads/files/1445851485.pdf
    • http://cssh.es/img/file/texipiwigurubexed.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_off0000c82a.bin
e5f96fe614a1b7ca68b2d2e89876546abe090b9a827d8b4031308bb205320b55
pdf-font-stream PDF embedded font (sfnt) at offset 0xC82A 17424 bytes
font_01_sfnt_off0000f4ff.bin
34e47710298acc4b10eeb6e0679e7ff6a020eaef61f13837b46dbb5b35777ee7
pdf-font-stream PDF embedded font (sfnt) at offset 0xF4FF 10900 bytes
font_02_sfnt_off00010e4b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E4B 16792 bytes