Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc8bc9d2da248896…

MALICIOUS

PDF

77.4 KB Created: 2021-09-02 03:16:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 04168331c57f9c4d53cf4c9d28fff442 SHA-1: 1df12c49a95d547194c09e66c2087caf2b2702ff SHA-256: bc8bc9d2da248896802a0a85fe93c4babf502c5c820976093b84c78c9b8a07bf
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, with numerous URLs pointing to various domains, some of which are hosted on compromised CMS upload directories. The PDF structure itself is heavily obfuscated, and while no scripts were explicitly extracted, the presence of external URI firings and the overall nature of link farms suggest an attempt to redirect users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9934

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://samirkumarpaul.com/ckfinder/userfiles/files/12520639137.pdf In PDF document text
    • https://costabravas.com/uploads/localidades/files/ludinijaveluwumuwusuziko.pdfIn PDF document text
    • http://deccanquest.com/konadnew/userfiles/file/65750908303.pdfIn PDF document text
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072363c7428f---kopebelebeminiki.pdfIn PDF document text
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/43riua70s1vmh3t0sfb1leff0p/wumekevudafulimapesodiviw.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607f65c1eca75---liwalinajuwiro.pdfIn PDF document text
    • http://birizgardenhotel.com/userfiles/file/35044952551.pdfIn PDF document text
    • http://ptaki.info/imgekoprojekty/files/pifezawefomezojozodupamut.pdfIn PDF document text
    • http://www.suffaheducation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a04be798a49---pevevabugobenefajuziz.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac454b1278c---xozawasefareman.pdfIn PDF document text
    • http://theorientgarden.iorderfoods.com/uploads/files/10458125650.pdfIn PDF document text
    • http://alternatifhirdavat.com/upload/ckfinder/files/xozibowogebumedover.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/a4773dc783f3bf3fc8c7b588af51d585/10406724744.pdfIn PDF document text
    • http://chromavials.com/d/files/jusezokis.pdfIn PDF document text
    • http://anhuizpyy.com/upload_fck/file/2021-6-10/20210610124219468631.pdfIn PDF document text
    • https://yingzhaoliuart.com/upload/file/53349050810.pdfIn PDF document text
    • http://print-resource.co.uk/ckfinder/userfiles/files/funebebi.pdfIn PDF document text
    • http://gildiamasterov.ru/userfiles/file/kejizotomidotibuled.pdfIn PDF document text
    • https://fiscconsulting.com/userfiles/file/xexudulevegabolozutifiwij.pdfIn PDF document text
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/23e921b0ef900e142e4029e818a0987a/75008564209.pdfIn PDF document text
    • http://inbond-cn.com/userfiles/file/73161313587.pdfIn PDF document text
    • http://arcadia6465.com/clients/f/fc/fcac8d81e62e7f23ed02b02243def538/File/piridixibikifuxabawa.pdfIn PDF document text
    • https://ubitanduk.com/contents//files/41349528587.pdfIn PDF document text
    • http://brickform.cz/obrazky/files/nigolerogimadi.pdfIn PDF document text
    • http://pgnsualumni.com/clients/872691/File/66908950015.pdfIn PDF document text
    • https://solener.info/ckfinder/userfiles/files/8691419205.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=want+to+proceedPDF 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_off0000c2ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2EE 10196 bytes
SHA-256: c1f59de765614180c662f4654dfcf7f780b6de5d17ece52806409194e309adca
font_01_sfnt_off0000d9ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9EA 19576 bytes
SHA-256: d1a0c9c32ee394aad0a6a288c0cc032ec98f6010d0516dbeefaab3ef15ee0049
font_02_sfnt_off00010d97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D97 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1