Malicious PDF — malware analysis report

Static analysis result for SHA-256 3e7660bc62f8aa7f…

MALICIOUS

PDF

83.5 KB Created: 2021-09-13 21:47:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5a1cb28fc59f44d4024732978341d4c0 SHA-1: 69557ae80ffab24dde1f68823abc8c5fa72bd169 SHA-256: 3e7660bc62f8aa7f77050148ffc1581afefcf0b66abce701e24e755b995eb131
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to PDF files on different domains, indicating a link farm or distribution network. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM further supports this, noting the presence of many distinct hosts and links. While no scripts were explicitly extracted, the nature of the embedded URLs and the ML detection suggest a malicious intent to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://form4concrete.ru/pics/cont/file/zulagudadumojurevojodezuv.pdf In PDF document text
    • https://emenu.hu/editor_up/nogarexiximari.pdfIn PDF document text
    • http://freeorden.com/media/file/tubegilixesel.pdfIn PDF document text
    • http://daiichigroup.net/uploads/news_file/10404949863.pdfIn PDF document text
    • https://sieuviet.net/webroot/img/files/70429505030.pdfIn PDF document text
    • http://revize-elektro.info/UserFiles/File/dosujupebewusafejod.pdfIn PDF document text
    • https://xosobacninh.vn/webroot/img/files/dulujekoriz.pdfIn PDF document text
    • http://moutierrozeille.fr/userfiles/file/japuzososaval.pdfIn PDF document text
    • http://studiotecnicodavico.eu/userfiles/files/fuwepugewewimikezuxalu.pdfIn PDF document text
    • http://motorlustor.net/userfiles/file/57363697359.pdfIn PDF document text
    • https://nichecnk.leaddeehub.com/userfiles/files/nexizoxivotogevasili.pdfIn PDF document text
    • http://www.accl-calibration.com/login/ckfinder/userfiles/files/89062240192.pdfIn PDF document text
    • https://nocnepal.org.np/ckfinder/userfiles/files/feruginobek.pdfIn PDF document text
    • http://zhizhencn.com/filespath/files/20210910051902.pdfIn PDF document text
    • https://hanurichurch.org/ckfinder/userfiles/files/62788345347.pdfIn PDF document text
    • http://pataibicaj.hu/userfiles/file/75047235090.pdfIn PDF document text
    • http://sity-luxe.ru/userfiles/file/90236061286.pdfIn PDF document text
    • http://instant-image.net/UserFiles/Site/File/zukexamomowobodipagilixe.pdfIn PDF document text
    • http://mrhobbscoffee.com/images/uploads/file/24284142653.pdfIn PDF document text
    • http://hrzservices.com/uploadfiles/file/67109424994.pdfIn PDF document text
    • https://www.karavanlakesfet.com/wp-content/plugins/super-forms/uploads/php/files/42ec1427c6a8f22c02996aae17b71200/jubepugabewifujonoj.pdfIn PDF document text
    • https://et-auditing.com/userfiles/files/21328258663.pdfIn PDF document text
    • http://mea-travel.pl/userfiles/file/fuluf.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/161307c1facd78---nudobo.pdfIn PDF document text
    • https://homeuu.biz/upload/ckeditor/pages/files/83435723524.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=video+pro+apk+downloadPDF 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_off0000e1fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1FB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fa12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA12 10268 bytes
SHA-256: a27e66d2bada44b6ac330d92c071777eccda79cf3810875b572ec5da50d3c717
font_02_sfnt_off0001113b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1113B 18256 bytes
SHA-256: 5aac52eaad68133c3c0212283f6fa84d17d0593ee11e38d0c3a97a51ebce4530