Malicious PDF — malware analysis report

Static analysis result for SHA-256 5fb531a2d5163904…

MALICIOUS

PDF

80.1 KB Created: 2021-09-09 13:21:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 516b825df15668b0e931530031d072c6 SHA-1: 55de4e9a0b39b0d5856513766491dc33d6861cf5 SHA-256: 5fb531a2d51639046f15a52595252918b1b27e6dc362fd1134c6dd0fb123c915
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised WordPress sites, indicating a link farm designed to distribute malicious content or phish users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 6

  • 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 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=reset+network+settings+android+9 PDF link annotation
    • http://shyjjc.com/v15/Upload/file/202192115839776.pdfIn PDF document text
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612f49dd574e7---numipozipumajefokinawuwe.pdfIn PDF document text
    • https://adamant54.ru/userfiles/files/lagetufabimej.pdfIn PDF document text
    • https://thaiwoodengames.com/files/upload/files/511824304.pdfIn PDF document text
    • http://aminotp.com/upload/files/31529619097.pdfIn PDF document text
    • https://www.jaegeraviation.com/ckfinder/userfiles/files/88350544008.pdfIn PDF document text
    • http://kdsonline.org/userfiles/file/3350674659.pdfIn PDF document text
    • http://picassogift.com/Uploadfiles/files/68590012219.pdfIn PDF document text
    • https://hfbee.tw/upload/ckfinder_temp/files/20210909125849.pdfIn PDF document text
    • http://qhzs88.com/admin/fckeditor_upfiles/file/2021090303495880554.pdfIn PDF document text
    • https://strings97.hu/userfiles/file/95851661545.pdfIn PDF document text
    • http://espicycooking.com/files/file///tutudemufofugaxowox.pdfIn PDF document text
    • http://1careglobal.com/upload/files/suwikibapavinexixedu.pdfIn PDF document text
    • https://prestinieurope.ch/userfiles/files/jerukuvijapigepozan.pdfIn PDF document text
    • http://kozszemle.hu/uploads/files/kaketefeseretixotorasex.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612f2867ade4b---nigonuvaz.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613625fac9dfc---rinuwavutakifibojudilago.pdfIn PDF document text
    • http://pamatudarbai.lt/ckfinder/userfiles/files/dumuxezasusanofo.pdfIn PDF document text
    • http://shinaval.ru/userfiles/file/loxawivukibeligaxenivo.pdfIn PDF document text
    • http://dungcubepgiangtrinh.com/webroot/img/files/38056689133.pdfIn PDF document text
    • https://anzhero-sudzhensk.verlauf-ekb.ru/admin/ckfinder/userfiles/files/dajadavowupabum.pdfIn PDF document text
    • https://doctmcooper.com/userfiles/files/96189086259.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_off0000d391.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD391 10768 bytes
SHA-256: e58308ce79078e4ff4c11c400f0e6794ccf75b51903a50565d34540c6090edf6
font_01_sfnt_off0000ec6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC6B 17916 bytes
SHA-256: d2674f93fc8d1ce2e358eaeae9c6c4ad785640904e810cc2de7c0ca7e73f2b99
font_02_sfnt_off00011b0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B0A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1