Malicious PDF — malware analysis report

Static analysis result for SHA-256 8be428d735e91a7c…

MALICIOUS

PDF

71.7 KB Created: 2021-09-25 01:09:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-07
MD5: cdbb337a2710d0df03264e8e9c472524 SHA-1: 60aaf660c677ffd31989aecade81d2ff79880d48 SHA-256: 8be428d735e91a7cf5062edea4ba6b324c3c7e39181049c29be5d9b8164d052e
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple disposable hosting sites, likely to download further malicious content. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM firings supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://butyfarm.mm520.net/userfiles/files/jujolalumizan.pdf In PDF document text
    • http://amandamaitland.com/images/file/88593769843.pdfIn PDF document text
    • http://maychamsocda.vn/images/userfiles/file/dogugoled.pdfIn PDF document text
    • http://www.addvanceo.info/userfiles/files/91508991553.pdfIn PDF document text
    • http://silarperu.com/UserFiles/file/kiwatelumuze.pdfIn PDF document text
    • http://tzoetemondje.be/uploads/files/51860927395.pdfIn PDF document text
    • https://alarouba.com/ckfinder/userfiles/files/faropad.pdfIn PDF document text
    • http://pwr-tech.ru/userfiles/file/wakifumiwox.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/fng09oabid13tsh6ebgf09jip1/zitaxefe.pdfIn PDF document text
    • https://taxforce.nl/userfiles/files/12585962345.pdfIn PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614be24b5060e---tiwagisobabodilut.pdfIn PDF document text
    • https://allianztc.ro/files/file/43603508205.pdfIn PDF document text
    • http://tatugigo.com/ckfinder/userfiles/files/23219383545.pdfIn PDF document text
    • http://pentas.eu/userfiles/file/39394545942.pdfIn PDF document text
    • http://cestovni-postylka.eu/userfiles/file/fatiditidiwefolafuxalo.pdfIn PDF document text
    • http://elverum-revmatiker.no/images/file/menijixizuxafetesog.pdfIn PDF document text
    • https://slotpt2.com/contents/files/52020502807.pdfIn PDF document text
    • https://cli-kh.com/uploads/files/202109031800588531.pdfIn PDF document text
    • http://food-cloud.com/home/food-cloud/www/site/site/data/files/28231483878.pdfIn PDF document text
    • https://inprovitvenezuela.com/ckfinder/userfiles/files/dipefel.pdfIn PDF document text
    • http://wish-pharma.com/upload/files/27688593811.pdfIn PDF document text
    • http://studiotecnicoforace.eu/userfiles/files/wafedufisawofuroxibetaven.pdfIn PDF document text
    • https://northwestconvention.cz/data/files/20062705177.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134db85b0159---xisajenijuxex.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=crash+bandicoot+4+game+installingPDF 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_off0000b26f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB26F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA86 11064 bytes
SHA-256: c019eae687b3a23987af1c02d94525a50ae83ed89af48efff06088079da7c66b
font_02_sfnt_off0000e3ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3EC 16992 bytes
SHA-256: 3004c3521e2e8a753c874de9702518d7a07a1628f78244c711b6a7228137e54d