Malicious PDF — malware analysis report

Static analysis result for SHA-256 4acf5d54a4426ef6…

MALICIOUS

PDF

131.7 KB Created: 2021-09-05 16:23:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 14588fb3811e289e8bb5fb5a3ddbf6c9 SHA-1: 7e3be46b794afd12105cf510522ae0e09460c801 SHA-256: 4acf5d54a4426ef62418e871dcdb35d606882938a2c74937aa2dd253f69c6d9f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document flagged by ClamAV and an ML classifier as malicious. It contains numerous external links, many pointing to compromised WordPress sites, suggesting a link farm or phishing lure. The presence of embedded URLs and the nature of the heuristics indicate that the PDF is intended to redirect users to malicious sites, likely for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9944

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://nomylo.ru/uplcv?utm_term=honda+brio+service+manual+pdf
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/d0e6a5f9b3040bb34a6dab4192adff58/sababomivekale.pdf
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4d75e741a4---36467194740.pdf
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16076300b0333e---49748869387.pdf
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160f863ccaffbd---patenewiputofivibejuvo.pdf
    • https://swagath.co/new/ckfinder/userfiles/files/9124488741.pdf
    • http://g-shocktou.com/user_file/file/bamarunotufus.pdf
    • https://equantumconsulting.com/files/files/wufumorikatabokixilop.pdf
    • https://www.tunnel.de/files/uploaded/file/nenijakonazoxikatuvo.pdf
    • https://ehotelgateway.com/bot/ckfinder/uf/files/sofedapuzusi.pdf
    • http://medob.org/SITE/files/editor/file/591170105.pdf
    • http://asja-doll.ru/userfiles/file/foziteg.pdf
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/09bca515f6fcde218ec124c8e0ba4c5e/93880474027.pdf
    • http://ownlines.com/upfiles/file/93162341957.pdf
    • https://carstenrath.com/wp-content/plugins/super-forms/uploads/php/files/vokjunfstjhricjpjt3plqen0l/fegebewuvaxotebilixanoni.pdf
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd43348490e---sivadogelerujesavoxa.pdf
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160cac6dd7e969---fekaxepudibojaxorewotix.pdf
    • http://thaimassageboy.com/ckfinder/userfiles/files/temoritobofegepiviru.pdf
    • http://alisawedding.com/upload/users/files/22865630653.pdf
    • http://lamgi.pl/ckfinder/userfiles/files/rodukepiniwazisamaze.pdf
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/160720ece05fd4---57604589541.pdf
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160840f914bdf6---luwuxazometuvati.pdf
    • https://dm288.rs/slicice/file/53079390434.pdf
    • https://rux-thai.com/ckfinder/userfiles/files/supab.pdf
    • http://zonazero.es/userfiles/file/debikisibawi.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_off00019995.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x19995 16792 bytes
font_01_sfnt_off0001b1ac.bin
6f56c963d2327089275c9033e695cc4039edf56aa92d128579f4c2f33f817235
pdf-font-stream PDF embedded font (sfnt) at offset 0x1B1AC 10980 bytes
font_02_sfnt_off0001cae0.bin
5a62fde339e3b610bee1f3a502a2819857250cee3c52dc11c7b6269c2fc168ad
pdf-font-stream PDF embedded font (sfnt) at offset 0x1CAE0 20632 bytes