Malicious PDF — malware analysis report

Static analysis result for SHA-256 899bdc3fc3751716…

MALICIOUS

PDF

72.1 KB Created: 2021-09-18 16:52:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: f0cd95a2efbf365cf566af425de2b514 SHA-1: 20b6ebbec152bb520a4f80337aa978ff11a7bafd SHA-256: 899bdc3fc3751716f802414fce88a7eedacfa6436ba7c4b08e8c472182161335
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links to external websites, many of which are hosted on compromised or disposable 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 distribution. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 http://tomaszfilipczak.pl/userfiles/file/tabuxoxusuvalurug.pdf In PDF document text
    • http://roycraft.ca/userfiles/file/nugexitajofovof.pdfIn PDF document text
    • https://kolorubursztynu.kolorubursztynu.pl/web/uploads/files/92910485788.pdfIn PDF document text
    • http://goodmax.ru/i/files/lipoxorap.pdfIn PDF document text
    • http://dolonchem.com/upload/files/kusofixevisavizawixiz.pdfIn PDF document text
    • http://jongauger.com/userfiles/file/wumojozuwodejagediziw.pdfIn PDF document text
    • http://azbuka-d.ru/ckfinder/userfiles/files/98176214084.pdfIn PDF document text
    • https://onlinendttraining.com/files/18740765686.pdfIn PDF document text
    • https://www.jaegeraviation.com/ckfinder/userfiles/files/82346017384.pdfIn PDF document text
    • https://clarkfamilybuilders.com/home/clark/public_html/ckfinder/userfiles/files/96605426967.pdfIn PDF document text
    • http://ijfbn.com/editor_up/27570428782.pdfIn PDF document text
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/5081864a98c237d8b05ef4e8b590eb64/ripojizuxu.pdfIn PDF document text
    • http://ranahytta.com/ckfinder/userfiles/files/61020097265.pdfIn PDF document text
    • http://100gastro.cz/soubory/files/89585189715.pdfIn PDF document text
    • http://xn--80age2amlc.xn--80adxhks/pics/images/file/berinedanofonux.pdfIn PDF document text
    • http://parfumland.sk/upl/dapoliwoxijaz.pdfIn PDF document text
    • http://pixel-pro.ru/upload/file/pezika.pdfIn PDF document text
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/26f027oqk4d6v6v8hb7ba5cirv/92863248493.pdfIn PDF document text
    • http://thestarbusan.com/FileData/ckfinder/files/20210917_119C83DB0282D9AE.pdfIn PDF document text
    • https://wyslijpaczki.pl/app/webroot/files/userfiles/file/82548636175.pdfIn PDF document text
    • https://spirit-legend-enterprises.com/webroot/editor-uploads/files/47690552229.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141a5652ff4f---10364533239.pdfIn PDF document text
    • http://anais.terminarz.online/kosmetyczka/krakow/files/nizozu.pdfIn PDF document text
    • https://kawanmto.org/contents/files/31275321504.pdfIn PDF document text
    • http://gandolfiarchitetti.com/userfiles/files/67558197933.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=psiphon+vpn+apkPDF 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_off0000b506.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB506 10132 bytes
SHA-256: e5ebd153d3fe68a574eb5933efbc21faf2353d2d8fef6dcc39bfcaea7190640a
font_01_sfnt_off0000cb95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB95 19072 bytes
SHA-256: 5a084f7589bd8c94c1c52d85ff4a88386abe40046f864c6add5f557505a1eaec
font_02_sfnt_off0000faf9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAF9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1