Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b5a459f78f968f3…

MALICIOUS

PDF

73.4 KB Created: 2021-09-17 15:20:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: ba9372d3c4ec3830ef858ded84d7c215 SHA-1: 4874aef62ed21615bc76383297c474dff857aaa2 SHA-256: 3b5a459f78f968f31e7f0edcbc6602af66a7a4ec8d86c7c22d07d05f7983a262
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to external websites, many of which are hosted on compromised or disposable domains, indicating a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the nature of the links and the ML detection suggest it's likely designed to exploit vulnerabilities or deliver further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://sikdercollegeofpharmacy.com/scp/ckfinder/uploads/userfiles/files/12365687538.pdf In PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/16137df65a4baa---61533463884.pdfIn PDF document text
    • https://ctapigroup3.com/contents/files/71262103043.pdfIn PDF document text
    • https://maria-galland.ru/files/file/93359327856.pdfIn PDF document text
    • https://cuatudongsaigon.vn/uploads/files/48008923210.pdfIn PDF document text
    • https://thietbivesinhanhhuy.com/asset/files/godikubaxewivojorezalaj.pdfIn PDF document text
    • https://amrapalispot.com/userfiles/file/15573812553.pdfIn PDF document text
    • https://soosekszer.hu/upload/files/kebumesa.pdfIn PDF document text
    • http://euroambulans.pl/userfiles/file/pefekejorefabugibiruveb.pdfIn PDF document text
    • http://adidravidar.com/ckfinder/userfiles/files/kasarupebamul.pdfIn PDF document text
    • https://kaptenhoki.net/contents/files/45103745985.pdfIn PDF document text
    • https://xn--b8qxb801j.tw/upload/files/tizoturiwudowurojimol.pdfIn PDF document text
    • https://nezrenpin.com/calisma2/files/uploads/92667845966.pdfIn PDF document text
    • https://doublehair.center/upload/ckfinder/files/15582075400.pdfIn PDF document text
    • https://jpt.mysmartedu.com/uploadimages/files/16456835155.pdfIn PDF document text
    • http://vaynhe.com/upload/files/jovoretusanezaworip.pdfIn PDF document text
    • http://lapmaymn.samdigroup.vn/app/webroot/upload/files/40326278359.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/2u46gt0pfuj79rqsvqsukvvhc0/fijujenemow.pdfIn PDF document text
    • http://www.logistiekverbeteren.nl/ckfinder/userfiles/files/31913559265.pdfIn PDF document text
    • https://sofahatinh.com/upload/files/kejiwoxo.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/161375b1387b84---mitotinijaxurufuzorowedi.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ed79969659---96198396542.pdfIn PDF document text
    • http://hp-cnc.de/uploads/files/ditigukujunov.pdfIn PDF document text
    • https://035620126.tw/upload/greenkitchen/files/zabarapinaruzozugu.pdfIn PDF document text
    • https://www.tzounakos-insurance.gr/ckfinder/userfiles/files/xuvositobabogojedomaza.pdfIn PDF document text
    • https://urbanshapes.in/userfiles/file/dugexejipetepalejum.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=tpb+fast+proxiesPDF 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_off0000bfd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFD2 10408 bytes
SHA-256: 93a46d249dfd88b7e9d5e6071361f2840899ddb61520f343df88e9aca5b14870
font_01_sfnt_off0000d758.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD758 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ef6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF6A 15984 bytes
SHA-256: f3744be68816ad1cdff97196cf46fe5db7234141034415e85f2d1985a44f7f28