Malicious PDF — malware analysis report

Static analysis result for SHA-256 a583b8cbcf91d681…

MALICIOUS

PDF

78.5 KB Created: 2021-09-01 03:37:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3aeaa8102418978ed3c09ada70007cf9 SHA-1: c2a272fde82402b27182b6f9fd519840655b2208 SHA-256: a583b8cbcf91d6814e62aacb337cb16493a2b058ad4085353485b121f49d7744
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress sites and disposable hosting, suggesting it functions as a link farm to distribute further malicious content or conduct phishing. The presence of embedded URLs and the nature of the heuristics strongly suggest a spearphishing attachment attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

Heuristics 7

  • 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.
  • 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://krisoc.ru/uplcv?utm_term=tom+welling+brandon+routh
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c290b9d721c---vikatunibuwemujunukovofoj.pdf
    • https://consultingexpert.eu/fckeditor/userfiles/file/51390289974.pdf
    • https://jjcfurnituremaker.com/userfiles/files/44917537276.pdf
    • http://51www.org/uploadfile/file/2a38500b41ee2c0b6bf46f77e8a4f0fe.pdf
    • https://karpzbeldowa.pl/uploads/userfiles/files/ximuvazojimika.pdf
    • https://www.digitalsofts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac8eb3e80e5---rajojolisofati.pdf
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082ba0a53dd0---wewokapilizipewetowa.pdf
    • http://www.pranabkumar.com/fckimages/file/mowirolire.pdf
    • http://wadsoda.com/UserFiles/File/38371274105.pdf
    • https://lostsoulsmemorialnj.org/wp-content/plugins/super-forms/uploads/php/files/ee3c6eaff5ca79e58024cba058f02408/rimuwafubisuza.pdf
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/07gu172ondvimu0t83tnbn6q02/96421245588.pdf
    • http://brlairport.com/images/file/goxarotojidetofudovofu.pdf
    • https://www.emma-solutions.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a03bc4c6d4f---26517911532.pdf
    • http://alimentosldm.com/userfiles/file/rumijulitomiruforegekori.pdf
    • http://datavincity.com/uploads/ckfinder/files/28287339966.pdf
    • http://birnagarcollege.in/userfiles/file/26919323914.pdf
    • http://syuncyoku.jp/upload/file/rewogakovonobo.pdf
    • https://www.demetagras.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d17e69c966---gogug.pdf
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/8847756c5727e80926fd2d65742fee9f/mapisi.pdf
    • http://lobi.md/userfiles/file/fevugig.pdf
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/16098c28db40a0---ranelojewipopamijodevis.pdf
    • http://www.amanuttarakhand.org/ckfinder/userfiles/files/gokijelegoxu.pdf
    • http://doublehappyvstheinfinitesadness.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608de8fc803ab---1309645958.pdf
    • http://sgo-bage.com/public/files/files/55021876636.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_off0000cd03.bin
958fc41dc4f6132e67548773b734b99a3436bff7111f99db6b86b7c93b115f33
pdf-font-stream PDF embedded font (sfnt) at offset 0xCD03 10816 bytes
font_01_sfnt_off0000e588.bin
737dea61c264e651f2b0fe83e7c9797eddcd48396231e2f931d2b95636d5c576
pdf-font-stream PDF embedded font (sfnt) at offset 0xE588 17552 bytes
font_02_sfnt_off0001134c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1134C 16792 bytes