Malicious PDF — malware analysis report

Static analysis result for SHA-256 e9103139da2cbd78…

MALICIOUS

PDF

167.3 KB Created: 2021-09-09 21:37:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: eb78a2ba68b3d5827f9b843e411a792f SHA-1: 513f7ff5956b71f06763ff5b8d844aa9daf27d6b SHA-256: e9103139da2cbd78f65894e223c2d1ba7030727e57c9603863e358d5de7cb7d4
236 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, and exhibits high-risk heuristics related to random and compromised CMS URLs. The document's content, inferred from the 'SE_BROWSER_INSTALL_LURE' heuristic, suggests a social engineering attempt to prompt the user to install a browser extension or update. This is a common lure for credential theft or further malware deployment. No scripts were extracted, but the presence of multiple suspicious URLs indicates a likely attempt to redirect the user to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 8

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://brette-animation.com/userfiles/file/binadevedejise.pdf
    • https://mokhalasati.com/userfiles/files/nigefotixerofefuwilobag.pdf
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/949f818080f0887eef9e3b120d148cdc/reliremimuvigakakolixu.pdf
    • http://encino.ilovepokebar.com/uploads/files/41238218056.pdf
    • http://mesterteto.hu/userfiles/file/19609405811.pdf
    • https://oteaexpert.fr/cite_imgs/file/demoxatuzubiwakomov.pdf
    • https://auditorescr.com/ckfinder/userfiles/files/17845246353.pdf
    • https://sanaspinler.net/calisma2/files/uploads/40191115577.pdf
    • https://accounting789.com/ThImg/file/ziwobusexetuwimowosap.pdf
    • http://koreanhotpot.com/uploads/files/revupijiduja.pdf
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/f6da0127b603ca805f84423f86f059f2/fogeni.pdf
    • https://al-wesam.com/userfiles/files/13069420703.pdf
    • http://edukoc.net/userData/ebizro_board/file/71251204721.pdf
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131d83ebe2f4---99221504656.pdf
    • http://studiomedicoveterinariobellucci.eu/userfiles/files/kugeroteba.pdf
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/56beo3r7r0mo8h614t72trjr1v/51903857967.pdf
    • http://ctkupavna.ru/upload/file/4068996130.pdf
    • https://agrilaui.com/userfiles/file/71661103589.pdf
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/161393d34db902---darizitetimunezava.pdf
    • http://alemotta.com/resources/original/file/80756293366.pdf
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/cilp6gapoi2tioualhmjm0esq0/22575028299.pdf
    • http://candientu24h.vn/webroot/img/files/mobebimegudipafow.pdf
    • https://rajatotogroup3.com/contents/files/volevunatovepuninefam.pdf
    • http://baby-daycare.com/uploads/files/202109040521019054.pdf
    • https://nikunjfoundation.org/ckfinder/userfiles/files/pisobokesetuzesiwibopukik.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=free+realms+minecraft+codes
    • 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_off0002227c.bin
f179aaed9911c4e417140eb45ef38ca0981701f535e3edb4c023a4ef3e5920c3
pdf-font-stream PDF embedded font (sfnt) at offset 0x2227C 10616 bytes
font_01_sfnt_off00023ab2.bin
2b84338cb920e8e98552884074b770af87462e53efd16c41b9856d71194b1156
pdf-font-stream PDF embedded font (sfnt) at offset 0x23AB2 22612 bytes
font_02_sfnt_off00027657.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x27657 16792 bytes