Malicious PDF — malware analysis report

Static analysis result for SHA-256 88c6631eb2dbd226…

MALICIOUS

PDF

76.1 KB Created: 2021-09-05 11:32:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 150ee014f2d200bdafc44182f3ec72e6 SHA-1: 648bac5b5f30f521ea3cba38bca6c13576e0f266 SHA-256: 88c6631eb2dbd226ae7bcd1af082c9c3af44beb3edd99c6ba3c0170d34f7d899
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or are part of a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lead users to phishing or malware distribution sites. The presence of multiple external links and the heuristic findings of a link farm on disposable hosting support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://dhsclassof70.com/clients/d/d1/d13f49183e6b2ef720c1f353b43de0f2/File/58898624701.pdf In PDF document text
    • http://fdscience.com/UPFILE/userfiles/files/21862273095.pdfIn PDF document text
    • http://ngpsusa.com/wp-content/plugins/super-forms/uploads/php/files/1oqrtblc71g21fc39r116tgpu9/wovezagikexato.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/33649029452.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/4fa2d0d6ae40969b514bc1ae8d816a51/bugamawukobi.pdfIn PDF document text
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/87fb386a7d102a7d0286f202ec8fee31/wovenamavuket.pdfIn PDF document text
    • https://ecole-anglais.com/upload/files/zusonuvosejikadimuzaremi.pdfIn PDF document text
    • http://kechengchem.com/upload/files/wesodifogadazuzagizome.pdfIn PDF document text
    • https://dodatnojamstvo.com/userfiles/file/15637443986.pdfIn PDF document text
    • http://studioarclab.eu/userfiles/files/zinamipikadodagufaxaso.pdfIn PDF document text
    • http://j-club.eu/userfiles/file/rukavafibufude.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/cnvd1tjb3bhaou70atur0u1tdr/xorotifefudufavij.pdfIn PDF document text
    • https://liniagdanskzydowo.pl/files/59880690558.pdfIn PDF document text
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160866acdb868f---wofefoxekamisuwu.pdfIn PDF document text
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/vmgpe6ecn067758f7mt35l49n7/gigugu.pdfIn PDF document text
    • https://indiantalentjunction.com/milan/media/meludexekasuzapive.pdfIn PDF document text
    • http://www.companyforte.com/imagenes/editor/file/43801589711.pdfIn PDF document text
    • http://rusiuojigalvoji.lt/wp-content/plugins/formcraft/file-upload/server/content/files/160be00460688e---9199789196.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607803495e563---wuwenimanotiruwu.pdfIn PDF document text
    • https://teenvolunteerdallas.org/wp-content/plugins/super-forms/uploads/php/files/513d5b013c8cf93a94ebbc6befff885b/20460522266.pdfIn PDF document text
    • https://cooperspick.com/files/vemagorekixi.pdfIn PDF document text
    • http://assytekservizi.com/userfiles/files/fubapobodulazip.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adc4a2497b8---58102180699.pdfIn PDF document text
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/c6bb197f0075ffa1d1403a9b2609ff81/41181519668.pdfIn PDF document text
    • http://strahovka66.ru/userfiles/file/20303827972.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=schwyzer+griechische+grammatik+pdfPDF 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_off0000c206.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC206 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000da18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA18 18068 bytes
SHA-256: 1667bcc70ec63584f93daf72eeb45582fc858003fa70bee3fb8753def37d752c
font_02_sfnt_off00010874.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10874 11224 bytes
SHA-256: 404abb96596818a4a32b50b64b959cb26fe8454eacbc295ff456b62d9a4c102f