Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b3ae850c8f5257e…

MALICIOUS

PDF

76.3 KB Created: 2021-09-05 10:32:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 220d4e003f7d45add512b690d8ff44de SHA-1: 74aefc0e6a8aefe172437401ccb888fe0a9cca57 SHA-256: 4b3ae850c8f5257ef1992cc62a8ea214bd3db9eb822bedd6ffeafebb8097d2a4
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics indicate the PDF functions as a link farm, with many URLs pointing to compromised WordPress sites and potentially disposable hosting. These links likely lead to phishing pages or further malware downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160ecd34158bf1---58382648631.pdf In PDF document text
    • https://www.lightingsolutionsinc.net/wp-content/plugins/super-forms/uploads/php/files/de913f88661b687c7e278630e311735d/65174916953.pdfIn PDF document text
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/6f452958dd3fd305c2444ef62cf788d5/reveri.pdfIn PDF document text
    • https://landi-bg.com/images/file/kunifitoj.pdfIn PDF document text
    • http://brighterhealthcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/tunjme54tjsan2fiv2kp9m9sug/zepixo.pdfIn PDF document text
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/0c7a138bf1496ad1dfec46e5f871d055/rivukejapunudopopugituso.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160b82926dd6c1---nazewopuliwo.pdfIn PDF document text
    • https://smilaxlabs.com/userfiles/files/muxebovolaxuxosu.pdfIn PDF document text
    • http://udaybharat.in/ckfinder/userfiles/files/tejoxi.pdfIn PDF document text
    • https://sipare.com.ar/wp-content/plugins/super-forms/uploads/php/files/saqv0rofmge5oeb4hclfm6gnbk/9014335822.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133e0b2f1d79---34745130442.pdfIn PDF document text
    • http://wowbond.com/upload/Fckeditor/file/40746464349.pdfIn PDF document text
    • http://phenix-security.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16096885e29a1e---22114367856.pdfIn PDF document text
    • http://adabaskimerkezi.com/upload/file/zasuvone.pdfIn PDF document text
    • http://www.darvidproperty.com/news/file/13226365695.pdfIn PDF document text
    • http://buzmakov-ua.ru/admin/ckfinder/userfiles/files/sikejudasadowixawu.pdfIn PDF document text
    • http://inglewoodreunion.com/clients/68690/File/fubuwa.pdfIn PDF document text
    • https://absolut-fit-and-dance.de/wp-content/plugins/super-forms/uploads/php/files/usrg65dbdctu7t6a02d9sve536/92506959339.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abcda8f380e---46576579355.pdfIn PDF document text
    • https://www.techsrollout.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9781466075---36833716708.pdfIn PDF document text
    • http://xn--szabowski-tub.pl/userfiles/file/gejikugasafitufe.pdfIn PDF document text
    • http://pcmcpropertyblog.com/wp-content/plugins/super-forms/uploads/php/files/1490b8c86f8815dc7c8b770e99ffaaac/98779597085.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/e5214dddb1c4996ac393e8a0f429541a/11653762053.pdfIn PDF document text
    • http://cuacuonnhanh.vn/Images_upload/files/rimujolilis.pdfIn PDF document text
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/jbrqsloqvm0r0v35i68kp9ictt/didatesefuluzo.pdfIn PDF document text
    • http://savvyais.com/userfiles/file/napagokivusubesuvokaxa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=english+idioms+esl+worksheetPDF 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_off0000c7df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7DF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dff6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFF6 10692 bytes
SHA-256: 0f636b4b40743cec7a16bb8496f388103dbe506d52e6e986e0768895e039241f
font_02_sfnt_off0000f811.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF811 16964 bytes
SHA-256: 4ecaec6f40bcb6e2a855da69b89704036d1658ee2702fd566081d1c7697ac099