Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4fba81ade6349b8…

MALICIOUS

PDF

91.2 KB Created: 2021-06-28 20:48:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5f34433c55b8b4847603e2634c4809e7 SHA-1: ea6b2454d41c4daa4df51e39145eb11a2682eaca SHA-256: c4fba81ade6349b8bb295655ab5ecaa56305249c578883f9d2319c275766a6ac
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ML classifiers and ClamAV, specifically flagged as Pdf.Phishing.Trojan. It contains numerous embedded URLs that point to compromised CMS uploads and disposable hosting, suggesting a link farm designed to redirect users. The presence of these links and the overall structure indicate an attempt to lure users to external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://queure.ru/uplcv?utm_term=have+an+insight+into
    • http://maxgear.cz/webpagebuilder/ckfinder/userfiles/files/zutotojatoden.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608303af44792---sisazidoku.pdf
    • https://alubiasdetolosa.com/files/galeria/files/58779373999.pdf
    • http://www.bufolari.com/public/immagini/file/73589734739.pdf
    • http://rbtyutj01.com/userfiles/files/54179524471.pdf
    • https://choiceenergynetwork.com/wp-content/plugins/super-forms/uploads/php/files/de35ca2c0d703fa34717ebfcad820007/46927672493.pdf
    • https://www.masismarketing.com/wp-content/plugins/super-forms/uploads/php/files/4f676c6f378d7e758e20a4ca4cb2729e/wuvaxuwomiduxafafosumasoj.pdf
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a04ef46768c---46524158548.pdf
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/b731d365a6a345b891a2a235dc872f62/pojuliganew.pdf
    • http://sequoia60.com/clients/875776/File/kenigof.pdf
    • https://ntwbearing.com/UserFiles/File/32317804560.pdf
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/ac2fe491ea6103ad46a838ff66e82d78/4051970653.pdf
    • http://wernitznigg.at/files/55257107699.pdf
    • http://timatey.kz/wp-content/plugins/super-forms/uploads/php/files/qnaf1dp830tak10dulvhnj9me3/6648515842.pdf
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607d250dbdab7---98048696200.pdf
    • http://broadviewlibrary.org/uploaded_bvlib/file/kagakilalebud.pdf
    • http://expertcomptablecourreges.fr/michel_courreges/userfiles/file/sojoxorigaxutumu.pdf
    • http://careerdynamic.com/clients/3/3d/3d9dba0a3645e5854abf1db7654b9c86/File/vepuveziwojopifibe.pdf
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160899ae93db66---xutupife.pdf
    • http://rzn-house.ru/upload/file/13295282127.pdf
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/160d241ba1e9be---nevaxujo.pdf
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/rloeqcuerl29dhoku4js1lsv15/visojifumusiluxewitujane.pdf
    • http://s8radziejowice-paszkow.pl/userfiles/file/nudebegu.pdf
    • http://pizzeria-millemiglia.de/app/webroot/img/editor/file/wixadim.pdf
    • 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_off0000fd92.bin
89d64d93bcddbf3ea460a7bedbde54f8f244b661d2283cf0999e4d6b4e597e5f
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD92 19384 bytes
font_01_sfnt_off00013075.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13075 16792 bytes
font_02_sfnt_off0001488c.bin
1daae566497528fa76d3b9282604804d2f729c8f1a1027bd77df2abbf9520fb7
pdf-font-stream PDF embedded font (sfnt) at offset 0x1488C 10296 bytes