Malicious PDF — malware analysis report

Static analysis result for SHA-256 2e837f435ada748d…

MALICIOUS

PDF

88.7 KB Created: 2021-08-13 03:46:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ecdd732ed8bb6c4b3f91ad1e748ef8ce SHA-1: 4f3da70b8b372841b020dd11ca8b856514bb7a94 SHA-256: 2e837f435ada748dae9380e9e8348ae0956a4e9d1122f6f1dae88670c02f1c1f
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 embedded links, many pointing to compromised WordPress sites and disposable hosting, suggesting it functions as a link farm to distribute malware or conduct phishing. The presence of PDF_RANDOM_URL_LINK and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9919

Heuristics 7

  • 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 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 http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae7a6f715b0---3368400592.pdf
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/1e6fdc2d35d93cb80f96137e396bb9ab/87101965459.pdf
    • https://www.adoz.cz/ckfinder/userfiles/files/68826150291.pdf
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/14ee12d63145656eaefa51f9d2187652/lozotuzanuvumi.pdf
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/t7279td5r9r4uehs3kspnohu4c/97123999171.pdf
    • https://pharmnet.cz/ckfiles/files/files/31396276654.pdf
    • https://pousadamarazul.tur.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609403f35287b---11516850201.pdf
    • https://jbdclothiers.net/emailer/userfiles/file/tirusamibewegoziki.pdf
    • http://joyear.com/ckfinder/userfiles/files/6063072735.pdf
    • http://elonsummerstorage.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072c0b6acb43---vekiduxu.pdf
    • http://bellina.pl/userfiles/file/62248062545.pdf
    • http://jinxinghotel.com/uploads/files/zusuzazenuzurulaf.pdf
    • http://onlinemidias.com/ckfinder/userfiles/files/tasabazuvegopu.pdf
    • https://www.geo-decouverte.com/ck/ckfinder/userfiles/files/godafujujikozotizobor.pdf
    • http://doublehappyvstheinfinitesadness.com/wp-content/plugins/formcraft/file-upload/server/content/files/160795d4bda3cd---55280370457.pdf
    • http://jirehenl.com/userfiles/file/280523169086.pdf
    • http://dlastudenta.org/Upload/file/68847979067.pdf
    • https://vestol.bg/files/file/dokerixotilusewus.pdf
    • https://eyestech.in/wp-content/plugins/super-forms/uploads/php/files/8oc29g021c9ckdp4gogn055b2f/45982926542.pdf
    • http://bjeclinic.com/ckfinder/userfiles/files/896093243.pdf
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/160bfc636d4950---83972783228.pdf
    • https://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/e3brh1cj312imbirlhi55a2lu4/45760669221.pdf
    • http://makesrealsense.com/ckfinder/userfiles/files/64970474803.pdf
    • http://cityhighclassof77.com/clients/9/9e/9ea685038b5a197d2022a69b8c6b162a/File/meligisonid.pdf
    • https://heks-tech.com/app/webroot/userfiles/files/50332822088.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=short+stories+in+english+for+intermediate+students+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_off0000f622.bin
fbc02149c5035e76b96df65d5e7b531a4ddb050b91ffbcbb78fe05f58adcd7ee
pdf-font-stream PDF embedded font (sfnt) at offset 0xF622 11120 bytes
font_01_sfnt_off00010fab.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10FAB 16792 bytes
font_02_sfnt_off000127bd.bin
c34c392e731491c0b17113ea23d8fc2b999053705c72ea3844f372e737355cbb
pdf-font-stream PDF embedded font (sfnt) at offset 0x127BD 16872 bytes