Malicious PDF — malware analysis report

Static analysis result for SHA-256 838b3ced6472a8d5…

MALICIOUS

PDF

86.4 KB Created: 2021-09-20 09:07:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: dc40d6e326e3ad61e200c494e51a67aa SHA-1: ce42fd1454813e536a5d0c1822da561ce544018a SHA-256: 838b3ced6472a8d5a69a62b30edace76dc274dcb60529a7b152c0db19625f0dd
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to redirect users to potentially harmful content. The presence of these links and the heuristic firings strongly indicate a phishing or malicious redirection attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://egyiksem.hu/uploads/file/39086967295.pdf In PDF document text
    • https://kcss.hu/korosi/userfiles/file/12957169710.pdfIn PDF document text
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/4c762903c2b457d11962b392d271bae7/segidakalufejopegelugeru.pdfIn PDF document text
    • http://dkind.net/userData/board/file/jokunapesuboreredegizuk.pdfIn PDF document text
    • https://zniczekowalczyk.com/user_images/file/9066081030.pdfIn PDF document text
    • http://agataklimowska.pl/userfiles/file/liwaxoteminugexi.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613174de8092d---39399625925.pdfIn PDF document text
    • https://fidelishospice.com/ckfinder/userfiles/files/15683794188.pdfIn PDF document text
    • http://chatfieldfarms101.com/userimages/99451490978.pdfIn PDF document text
    • http://szzxwx.com/Upload/Upload/file/20219141423143606.pdfIn PDF document text
    • http://vietxetai.com/wp-content/plugins/super-forms/uploads/php/files/l0d3lgpdm783b9knd5nm83iu8s/16390748460.pdfIn PDF document text
    • https://mimpishio1.com/contents/files/75752668213.pdfIn PDF document text
    • https://ladangmimpi2.com/contents/files/59362786808.pdfIn PDF document text
    • https://fullprotec.com/ckfinder/userfiles/files/wijajajadosazeviseso.pdfIn PDF document text
    • https://deshpanday.com/ckfinder/userfiles/files/dexonuvozaxago.pdfIn PDF document text
    • http://mofrantech.com/userfiles/file/zugeguteruwat.pdfIn PDF document text
    • https://gitimohammadilakhimpur.org/ckfinder/userfiles/files/72409865352.pdfIn PDF document text
    • http://goodlack.cz/userfiles/file/96267706574.pdfIn PDF document text
    • http://szyoujin.com/UploadFile/file/20210902191952217.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/hpf3pbnv5dfp9mrj65n2id5foc/voranokebixerogaxewi.pdfIn PDF document text
    • http://aan.kz/ckfinder/userfiles/files/ruwozefaz.pdfIn PDF document text
    • http://dytac.hk/userfiles/86346482280.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/1612ed229c8d54---wamefawifekugu.pdfIn PDF document text
    • https://biocenfis.es/uploads/assets/file/50603259997.pdfIn PDF document text
    • http://soleilboo.com/images/uploads/files/sasudowunapa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=windows+7+ultimate+x32PDF 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_off0000e6ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fec3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEC3 10932 bytes
SHA-256: c59cb47475ddaac623738b6a5d102cf6bb4b401c25bda42768571bf108a0f842
font_02_sfnt_off00011848.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11848 19728 bytes
SHA-256: 1430ba23d32314c50bafa2c19b5cd2c88ec124b7192d7e66e305946354b5d8f4