Malicious PDF — malware analysis report

Static analysis result for SHA-256 31c257993ba5ce5f…

MALICIOUS

PDF

90.6 KB Created: 2021-06-28 08:16:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b56d16f9196a2b9ea266bb405d4c2dce SHA-1: 57abc60578e6d8f10455dae17cde75881016d0c8 SHA-256: 31c257993ba5ce5fbaa15787c485155eceb7819d1cf711a37f85793af21f869f
196 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains a heuristic indicating it instructs the user to disable security software, a common tactic to bypass defenses. The document also functions as a link farm, with many URLs pointing to compromised CMS upload storage, suggesting it is used to distribute further malicious content or phishing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9822

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
  • Security software disable instruction high SE_SECURITY_BYPASS
    Document instructs the user to disable antivirus or security software — unusual for ordinary documents and high-risk in an unsolicited file
  • 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://invest.pl/userfiles/file/ruzulazutug.pdf
    • https://www.deuba.info/wp-content/plugins/super-forms/uploads/php/files/fp23evfdjj5u2ubvs1qhboccr1/8641219070.pdf
    • https://kudamatsu.org/userfiles/file/75746832364.pdf
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/1sobsdi976gdm2v55rbueq6nuf/83976237794.pdf
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b79f72dd078---96726543417.pdf
    • http://jar-ted.pl/file/85061648672.pdf
    • http://madmojo.com/fckupload/file/47645840420.pdf
    • http://saamfactory.com/wp-content/plugins/super-forms/uploads/php/files/caa3c39ba42d6dcda7b0b6bd2a18c577/povixifarejixutizipuduv.pdf
    • https://www.asahinadigital.com/wp-content/plugins/super-forms/uploads/php/files/snuc1qmialggghv428mqrvprb8/62199280534.pdf
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096354f412e4---tuxifufovelefozalufiwilu.pdf
    • https://alasclub.gr/neuro/ckfinder/userfiles/files/92268040889.pdf
    • https://fiambreszav.com/wp-content/plugins/super-forms/uploads/php/files/6177593c7ceab597d8eb0d029bdc295f/75719626191.pdf
    • http://bestofbeer.ru/ckfinder/userfiles/files/fidoruvalituwefogit.pdf
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4d3f47cb6e---11435283453.pdf
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/33435d432418ff49308da7b2759727a3/67486311947.pdf
    • https://lightsourceindiana.com/wp-content/plugins/super-forms/uploads/php/files/4aff50a3f52053526dc40429f826d1ef/maruwuwutebuxadobipes.pdf
    • https://protradingindia.net/userfiles/file/65416863002.pdf
    • https://dixietemporarystorage.com/wp-content/plugins/super-forms/uploads/php/files/58e31ad9b081d9483f1cceafbf279680/kokovetakuv.pdf
    • http://soldearenales.com/galeria/files/lijunifubixosa.pdf
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/3a037c8e0f535c5c094902550fe1c803/14464212423.pdf
    • http://kbchina.de/upload/migedamovowonolaborini.pdf
    • http://cmtdental.com/upload/ckimg/files/13720232382.pdf
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609b33cd964d4---53230943470.pdf
    • http://ever-pioneer.com/upload/files/powazizifilenevak.pdf
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/5a63gdod0iflip99k9m59jhiva/fegikivux.pdf
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160aa5a19152c5---61589674470.pdf
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/7c60e859195c305e8b2c0bba9270d332/71354029220.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=download+astra+pro+nulled
    • 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_off0000f787.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF787 16792 bytes
font_01_sfnt_off00010f99.bin
1c428ca28b100982654c966ab3524db8760fc5f5989d77ea048f4fd34dd15879
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F99 23924 bytes
font_02_sfnt_off0001452f.bin
9bb9241cd6ef339bf5184a3df6c72bf3e836fe758b863d25b84bc2e5735e4358
pdf-font-stream PDF embedded font (sfnt) at offset 0x1452F 10480 bytes