Malicious PDF — malware analysis report

Static analysis result for SHA-256 401c6b2703f82331…

MALICIOUS

PDF

81.9 KB Created: 2021-09-13 18:01:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 65c7de40587649b2e135198c069a4833 SHA-1: 96941a48e1d0f533852e31cf69270e211d100712 SHA-256: 401c6b2703f823318e7e5a14f468bd6a558cf85d961fc1aca15239b46bb99407
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains a link farm pointing to multiple compromised WordPress sites and disposable hosting, suggesting a phishing or malware distribution attempt. Embedded JavaScript was also detected, which could be used to further obfuscate the malicious intent or initiate a download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://valstybestarnyba.com/upckfinder/files/nebunavoge.pdf
    • http://studionegrelli.it/userfiles/files/jikogiverugaviwajuja.pdf
    • http://supair-lux.hu/ckfinder/userfiles/files/vikufamigazum.pdf
    • https://www.oasipizza.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613ddc7773c39---73675606314.pdf
    • http://tindangnhadat.vn/upload/files/49883968047.pdf
    • https://vayamcs.com/content_files/files/39755502948.pdf
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/16133e9fa09233---24520326396.pdf
    • https://bunianco.com/other_files/File/4088921962.pdf
    • https://shirbandifelt.com/userfiles/file/18594939141.pdf
    • http://euro520.net/userfiles/file/1631369284546488389.pdf
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161339b070313a---47617818276.pdf
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/804d8d8747c384a745f2fcd65fe67edb/figiwumifewapitigowuw.pdf
    • https://299-45.com/CKEdit/upload/files/lozepeluxu.pdf
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/f801d1eb545a340e24dd6d005f8b2423/71076505075.pdf
    • https://corcreation.twbiz.me/data/fckeditor/files/20210907_102357.pdf
    • http://rbc-bezorgdiensten.nl/upload/duguxiguradikokul.pdf
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/43d885f15ca98a093629aa96890d1eb0/bowujasijenupomulafenaso.pdf
    • http://quimis.org/js/ckfinder/userfiles/files/goxofereforifala.pdf
    • http://kramor.bg/userfiles/file/46578339204.pdf
    • https://abicecream.ru/ckfinder/userfiles/files/segorilulemizidudovurewe.pdf
    • http://citescolairedeledit.com/include/file/70490550709.pdf
    • http://adhunikjewellers.com/ckfinder/userfiles/files/75355738716.pdf
    • https://luckyfood.itweald.com/uploads/files/6139894a38052.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=con+ww3+mod+apk
    • 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_off0000dc66.bin
0b8ff721c1bda77cfc64ed9109548f4986d7e3ec46e3e37d791384474bcab827
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC66 10300 bytes
font_01_sfnt_off0000f3a3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF3A3 16792 bytes
font_02_sfnt_off00010bb5.bin
60eb9b712edb646955ac673768ea79a0608d84fadc296a8afb68a129112c5801
pdf-font-stream PDF embedded font (sfnt) at offset 0x10BB5 18008 bytes