Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a04dc51571a1b8a…

MALICIOUS

PDF

82.3 KB Created: 2021-09-16 19:59:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 677ab38dec876f43de979cd1a5425110 SHA-1: 1e46edf46c071fd78391227c409a9b97ec091c8a SHA-256: 8a04dc51571a1b8a562450fb04fd56b5dfe3fbb95b69c6a507f98258ba1caf6e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was identified as malicious by a ML classifier and ClamAV, flagging it as a phishing trojan. Static analysis revealed it functions as a link farm, with numerous URLs pointing to websites hosted on compromised or disposable domains. These links are likely intended to lure users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://gordostcrista.ru/userfiles/file/87244701833.pdf
    • http://zoo-foto.cz/userfiles/file/zozona.pdf
    • http://dakov.hu/_user/file/fenuzif.pdf
    • http://curry-box-deluxe.de/userfiles/file/95836436174.pdf
    • http://np-laser.com/upload_fck/file/2021-9-8/20210908053605265218.pdf
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/pdql9h42mqkfn8v4lqqt9as141/21209412775.pdf
    • http://deborahkay.com/ckfinder/userfiles/files/25322855568.pdf
    • http://xn--zb0bw3kv4s8mn.com/upload/fckeditor/file/femefozibopejemuganuvuju.pdf
    • http://ntouioc.ntou.edu.tw/ckfinder/userfiles/files/kewowaza.pdf
    • http://laboratorioshamalab.com/userfiles/file/92949606035.pdf
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134db6ebb3ee---tobedes.pdf
    • https://lanna-flyingclub.com/ckfinder/userfiles/files/dowutotipanab.pdf
    • http://jobcred.com/rk/jobcred/uploads/image/file/82678833797.pdf
    • https://www.hmgfinance.com/ckfinder/userfiles/files/titojodotelogapigifip.pdf
    • http://sevvalturizm.com/rsm/files/vopivikalun.pdf
    • http://pallenberg-busreisen.de/uploads/files/31899305048.pdf
    • https://stcc-sa.com/motakamel/Ups/files/somigalibitamiwilene.pdf
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/16132e0195aa7e---17724354918.pdf
    • https://floraplant.gr/FCKeditor/userimages/file/73294837537.pdf
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161403d26604ed---4179375260.pdf
    • http://vimbark.sk/editor_uploads/files/8003652127.pdf
    • http://domuran.pl/files/file/ganit.pdf
    • http://colleges-in-tamilnadu.com/FCKeditor/userfiles/file/1663881671.pdf
    • http://solarissoft.com/img/userfiles/files/filivifejun.pdf
    • http://theartofdesign.nl/ckfinder/userfiles/files/nuzerelamonikafi.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=doppler+effect+of+sound+formula
    • 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_off0000dcc5.bin
df304090b6996dcd73f75c16959ae938e4f52037ee157ba944de1c4521723582
pdf-font-stream PDF embedded font (sfnt) at offset 0xDCC5 10788 bytes
font_01_sfnt_off0000f5a8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5A8 16792 bytes
font_02_sfnt_off00010dba.bin
50c150f03a260e953ec316e8f4d52661f9cb917d68f602cc6f5cf18b4310e6ac
pdf-font-stream PDF embedded font (sfnt) at offset 0x10DBA 17468 bytes