Malicious PDF — malware analysis report

Static analysis result for SHA-256 4963cb0cd898678a…

MALICIOUS

PDF

87.0 KB Created: 2021-09-16 11:37:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: b401e30ecb97b311b4f6d3a76f2d1d4a SHA-1: 821cc17d81fcfa1c64cfaaba1a34e5b58700e12c SHA-256: 4963cb0cd898678a9634f62adf5dcc5ddb5134c8c97ac150df14b3b0df4f6558
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple external websites, some hosted on potentially compromised or disposable domains. The presence of numerous PDF links suggests an attempt to manipulate search engine results or distribute further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://probeg2000.ru/files/userfiles/files/78227114506.pdf In PDF document text
    • https://www.temtechnologies.fr/ckfinder/userfiles/files/48486273237.pdfIn PDF document text
    • http://sentai.cc/data/file/20210905_105526_944.pdfIn PDF document text
    • https://akamercedes.com/images/uploads/files/78502539992.pdfIn PDF document text
    • http://lenosada.sk/editor_uploads/files/20261429188.pdfIn PDF document text
    • http://inercial.es/uploads/files/67722256866.pdfIn PDF document text
    • http://thomas-zigon.de/images/file/lepanovudejajunitetak.pdfIn PDF document text
    • https://okinawa4d.com/contents/files/65732608648.pdfIn PDF document text
    • https://smsenerji.com/resimler/files/33267016567.pdfIn PDF document text
    • http://www.cenlajobinator.com/siteuploads/editorimg/file/72607950113.pdfIn PDF document text
    • https://huaienclinic.com/uploadpic/files/nidefel.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613ec033e7bc5---14183401285.pdfIn PDF document text
    • http://melly-incendie.fr/img_db/piwagekenitowasi.pdfIn PDF document text
    • http://symbioticlifetech.org/attfile/fckimg/file///2021091284327_674288257.pdfIn PDF document text
    • https://vr-spagna-20.effievirtual.com/galeria/files/23130864218.pdfIn PDF document text
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/0cb04c34ddcc1905c42471ec2bf35aac/ruwokavobukasolon.pdfIn PDF document text
    • http://af.ssla.ru/images/fornews/files/nufadurotuvuwomobamaj.pdfIn PDF document text
    • https://hkbca.org/UploadFiles/file/20210903104809200.pdfIn PDF document text
    • http://beijingxinzhi.com/userfiles/file/20210905182926_396866321.pdfIn PDF document text
    • http://warehousetraining.ie/images/22640456760.pdfIn PDF document text
    • http://makesomenoise.hu/upload/file/nerevadalaresofer.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/161364b673209c---potesoragoxusunuletavexa.pdfIn PDF document text
    • http://olympusflights.com/files/files/3851900396.pdfIn PDF document text
    • http://reklama-v-sochi.com/ckfinder/userfiles/files/popobufozawixutoz.pdfIn PDF document text
    • https://energiadirect.pl/application/resources/ckfinder/userfiles/files/67889559381.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=android+mod+menu+gamesPDF 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_off0000f34d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF34D 16784 bytes
SHA-256: a3e23f5f06b601263157b4393002a18cd1a13da0f99b38e2229e75589ff00d09
font_01_sfnt_off00011ee5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EE5 10528 bytes
SHA-256: 8247fea08c8e02e05a75c995c03bedc9a3394ad16dee01c6b1f15b270688d62c
font_02_sfnt_off0001369f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1369F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1