Malicious PDF — malware analysis report

Static analysis result for SHA-256 40ac4eca58f89c02…

MALICIOUS

PDF

85.0 KB Created: 2021-06-27 15:13:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: d62d4e01ab77e230299bcd95a433cd59 SHA-1: 6a4f8f0032f8a896a2fe446870b9e1cf1e668f54 SHA-256: 40ac4eca58f89c02527e03952ff686a11a5c16aeeb1ce43381448525e2368889
156 Risk Score

Malware Insights

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

The PDF contains numerous links to compromised websites, identified by heuristics as a link farm on disposable hosting and pointing to compromised CMS upload storage. ClamAV and an ML classifier also flagged this PDF as malicious, specifically as a phishing trojan. The embedded URLs suggest an attempt to redirect the user to malicious content, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/7r392t3tslvmt9lobaoi9s1mdh/14192625961.pdf In PDF document text
    • http://bamila.vn/luutru/files/vajixop.pdfIn PDF document text
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d1deb3dd662---soruwonazuwajegafukake.pdfIn PDF document text
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/160896b3c5eba5---japevulawodefupanulakod.pdfIn PDF document text
    • https://o-dance.com/upload/files/85118953259.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609ce43e8b8e7---90348645069.pdfIn PDF document text
    • https://www.bistro-e.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078797052c78---ruvewoputopodusimesoj.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/hq16oqfbeg5dm8rldv0udml5fp/9640793016.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607d2eb5f39f2---powofizukuruj.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/160ad859b72c76---86922598879.pdfIn PDF document text
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/4ti50elfvjvj8gs6lvap5ivddd/soletigokobatajin.pdfIn PDF document text
    • http://dermatologomiguelgallego.com/miguel/fck/file/viwerogopeb.pdfIn PDF document text
    • http://liburnia.pl/userfiles/file/63060004171.pdfIn PDF document text
    • https://www.webplease.it/wp-content/plugins/super-forms/uploads/php/files/retqbgh1fmdcm04c2cqmhjg9rb/fevosaxaxa.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/m2m4chnsml24bepompo1so3qt5/mulovo.pdfIn PDF document text
    • http://amandatravel.com/userfiles/file/36321519138.pdfIn PDF document text
    • https://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/a0dkk2ag2priulqbse7hu7epc1/tagugasozuvadajox.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076ffd7925b9---78735640311.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160c2df898090b---64052696107.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2c3e386ca2---berujisenibozumipomegu.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160c0428fc338f---43937042807.pdfIn PDF document text
    • http://relocationservicesgroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160770ac4104e8---45251662054.pdfIn PDF document text
    • http://lamachine.nl/userfiles/file/48133718302.pdfIn PDF document text
    • https://bikinibody.be/wp-content/plugins/super-forms/uploads/php/files/d054vji9n8oi9ff0sd37glg1gg/miwazogobatomero.pdfIn PDF document text
    • http://tuzvedo.hu/elemek/file/9796436495.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608208b449cf0---demuledoxutidomenulep.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=chevy+truck+manual+transmission+fluidPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA9A 11144 bytes
SHA-256: cab01e4d1141ee467b9902f7e627c5a3ef7c7b6de2000f0cc75d3bbb9d2a5dba
font_01_sfnt_off0001048c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1048C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011c9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C9E 16180 bytes
SHA-256: 84e0027f6c461d9f87d6ef8287837caffe737ab9d4572719d6a228b28573201d