Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8935547e9f8a1eb…

MALICIOUS

PDF

115.3 KB Created: 2021-07-22 09:28:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 0771e350e814fbb9507339d0e455f9fb SHA-1: 390952a473a35719cd97b9f99cad252cb24d5c1a SHA-256: b8935547e9f8a1eba73380b55e427ce2d99367b2779e393e639abc6a75f139bc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent. The primary function appears to be acting as a link farm, directing users to potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://tunglamgarden.com/images/fck/file/joxavugoxokopozuvimamube.pdf In PDF document text
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/212db5833679950487eb8f560b6b740f/furazudiluvafevedukiseri.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/03vfqf66beb9rckqj90truij1a/99845457884.pdfIn PDF document text
    • http://haumeaonline.com/userfiles/file/96915339475.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606f9e8430161---purilut.pdfIn PDF document text
    • https://bdsvieclam.com/upload/files/wujomavonudajaw.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/1feb959d659ff23f00902b6b376e25be/kavexiwojenonigemabela.pdfIn PDF document text
    • http://tea-ra.com/user_data/upload/save_image/files/vejimural.pdfIn PDF document text
    • https://asiaviews.org/wp-content/plugins/super-forms/uploads/php/files/lpi9jgsdh31qng3isairgg4dv2/25647376731.pdfIn PDF document text
    • http://ingenermarket.ru/userfiles/vifenewemutaz.pdfIn PDF document text
    • http://usmleworkout.com/files/file/26566552860.pdfIn PDF document text
    • http://riversedgefm.com/files/file/81133269789.pdfIn PDF document text
    • http://autoshiftbid.com/fckeditor/userfiles/file/63595118625.pdfIn PDF document text
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/7e4431ca485236289246fd6507c750fb/fugatumaramaligurujuv.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608d40d482ab7---satadetataguno.pdfIn PDF document text
    • http://bassbasement.org/userfiles/file/fakiguw.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/524d2343c8f365b26ddb2f7cb3ee6818/66231479135.pdfIn PDF document text
    • http://www.ambredore.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607de8ad7cfae---fuseg.pdfIn PDF document text
    • https://webmenuplus.com/images/file/90960282218.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/jn7uohcq9iuu47o8to6d3ppvka/60217339450.pdfIn PDF document text
    • https://bomnuocebara.com/quangbasanpham/app/webroot/upload/image/files/naxomokiw.pdfIn PDF document text
    • https://alkalacarservice.com/public_html/userfiles/file/paraneka.pdfIn PDF document text
    • https://abe-rdc.com/userfiles/file/jilasusupumuxo.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606d98aad9a7d---9172605672.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/hb7gnap904m679bpq5pp270724/kotugasubimusivipedofi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=computer+network+and+topologyPDF 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_off00015ffe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15FFE 17864 bytes
SHA-256: d00a289d686afc55a8bab1a7bc1bc7c14b8e35b327d90b52bafe20028c974ae8
font_01_sfnt_off00018e66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18E66 10900 bytes
SHA-256: 7bab261780a9375900e7c40885f10d39376f59eeb2d95233c7cccd2a8c5f0fd4
font_02_sfnt_off0001a77f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A77F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1