Malicious PDF — malware analysis report

Static analysis result for SHA-256 81a6115418674bb9…

MALICIOUS

PDF

91.7 KB Created: 2021-09-03 05:38:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 6825254bb6e42d6fbff3575697e0dd71 SHA-1: b8610d6f1501e4e69d4b94b8b8c393ccd8565154 SHA-256: 81a6115418674bb9b00f79cc1bef979b9dab9b54edaf80203a662c98d88c25c1
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to compromised WordPress sites and other domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. While no scripts were explicitly extracted, the presence of numerous external links and the 'compromised CMS upload link farm' heuristic point towards an attack pattern focused on redirecting users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://cructi.ru/uplcv?utm_term=camera+wifi+onvif+manual PDF link annotation
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/16075744aefdfa---zabotalofijutovoraved.pdfIn PDF document text
    • http://xn--e42bt3l.net/upfile/files/maxorag.pdfIn PDF document text
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/1e68bb2428aad8699f68c76ece7881af/zepavejila.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbac35ac93e---57440031195.pdfIn PDF document text
    • http://optykglowacki.pl/obrazki/files/38156505624.pdfIn PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/73f2c779c9b89092c2bae1a240261bca/bixozo.pdfIn PDF document text
    • https://restaurantenunti.ro/userfiles/file/kunamoraxawotep.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160acebe24adf2---88445049343.pdfIn PDF document text
    • https://mosconi.net/userfiles/file/57486110826.pdfIn PDF document text
    • https://www.igescanada.com/ckfinder/userfiles/files/47644080097.pdfIn PDF document text
    • https://aquafilling.com/userfiles/file/zajos.pdfIn PDF document text
    • http://zerosquareonline.com/file/64382345423.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609db8384c606---xalizuzewurubatinodil.pdfIn PDF document text
    • https://mgc.to/sites//web/upload/files/kalirubonerugulajajuxen.pdfIn PDF document text
    • http://paroissedementon.fr/upload/files/rozepidofet.pdfIn PDF document text
    • https://kidneystonetreatment.in/userfiles/files/22450775835.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c86a702298c---10082209614.pdfIn PDF document text
    • https://dewalt-naradi.cz/media/upload/editor/file/39335481851.pdfIn PDF document text
    • https://www.infrascale.com/wp-content/plugins/super-forms/uploads/php/files/d60a7e94fc0ee48ba36bb34e86a483be/97554760118.pdfIn PDF document text
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/9a98899aa2c2f259a8a5046379cdf0a8/79165174821.pdfIn PDF document text
    • http://robotsuk.com/luckingbros.co.uk/userfiles/files/30758487220.pdfIn PDF document text
    • http://j1medical.com/uploaded/file/loluxo.pdfIn PDF document text
    • http://tungalag.mn/userfiles/files/dupovotaxobazusi.pdfIn PDF document text
    • https://eltonltd.ru/sites/default/files/uploads/4901684422.pdfIn PDF document text
    • http://archiwum.wyryki.eu/admin/ckfinder/userfiles/files/67827177981.pdfIn PDF document text
    • 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_off0000feeb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEEB 19400 bytes
SHA-256: 5eba720fa6ad1c5b518093461a620fa36bcb9969184ce77b15caef0146b4858b
font_01_sfnt_off0001317c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1317C 10392 bytes
SHA-256: c4ae9ac7c4c0f1ca48ed1e7a764423b6ce2fda7c61d13d8b2e118a5566534dd6
font_02_sfnt_off00014901.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14901 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1