Malicious PDF — malware analysis report

Static analysis result for SHA-256 4008861dea77d9db…

MALICIOUS

PDF

92.8 KB Created: 2021-09-12 07:46:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: d91dd00163f31e4c85b6f5ab4db665bf SHA-1: cd8596dd0ee3f8f2bc6a8c704d25d101be4923ca SHA-256: 4008861dea77d9dbe36949f3b3c9b5b93930d3fdb580f0eaed5ff9cf6e11c593
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to various PDF files hosted on compromised websites, including a WordPress upload storage. The presence of embedded URLs and the nature of the heuristics suggest a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://bedandbreakfastchia.it/userfiles/file/59022776033.pdf In PDF document text
    • https://pracowniatechart.pl/fckpliki/file/dijezi.pdfIn PDF document text
    • http://alda.pl/ckfinder/userfiles/files/71924554586.pdfIn PDF document text
    • http://cicm2015.mist.ac.bd/app/webroot/ckfinder/userfiles/files/84518421852.pdfIn PDF document text
    • http://bestofbeer.ru/ckfinder/userfiles/files/50511009734.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f553c271e4---zifuvubinegixefijabiwej.pdfIn PDF document text
    • http://wxeina.com/userfiles/files/nuxidejuxozi.pdfIn PDF document text
    • https://jechrina.gr/FCKeditor/userimages/file/soxoloxe.pdfIn PDF document text
    • http://squash-fitness.cz/userfiles/file/67909848842.pdfIn PDF document text
    • http://minhphucvietnam.com/uploads/userfiles/file/72187454966.pdfIn PDF document text
    • http://www.mbk-montage.nl/ckfinder/userfiles/files/ruvizofodezejem.pdfIn PDF document text
    • http://lexen.ca/userfiles/files/vades.pdfIn PDF document text
    • http://technology-mp.it/userfiles/files/sazenufaxagadefopusep.pdfIn PDF document text
    • http://shrlie.com/upload_fck/file/2021-9-9/20210909081534922786.pdfIn PDF document text
    • http://chongthamnguoc.vn/img/files/45126836984.pdfIn PDF document text
    • http://boldogelet.hu/media/kavosanexom.pdfIn PDF document text
    • http://211.129.1.225/system/ckfinder/userfiles/files/56569367600.pdfPDF link annotation
    • https://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/614e568f9bd78924e22fb0b36266fe77/moxojon.pdfIn PDF document text
    • http://trustycctv.com/ckfinder/userfiles/files/68121527195.pdfIn PDF document text
    • http://stimatacasa.eu/userfiles/files/feliweju.pdfIn PDF document text
    • http://joesservicecenternj.com/userfiles/files/kisanabujiziguboj.pdfIn PDF document text
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613bf80b461ff---84256747173.pdfIn PDF document text
    • http://odesignlab.ru/admin/ckfinder/userfiles/files/16204728055.pdfIn PDF document text
    • https://samirkumarpaul.com/ckfinder/userfiles/files/56550946510.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16137d50546f11---57846071891.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=free+download+tekken+7+for+ppssppPDF 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_off00010409.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10409 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011c1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C1B 18552 bytes
SHA-256: 26a02f92a7c466658418b1cb51046a06aea9262293d0edd85734c528e89e72e9
font_02_sfnt_off00014c8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14C8F 10604 bytes
SHA-256: 0653da04ff02dc049049bdcfc022cea44d340d28dac72a0206160a62386c358f