Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef1cdc72902cd98a…

MALICIOUS

PDF

72.7 KB Created: 2021-09-26 06:20:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 084f38e9df83d4489c84c75815158d9b SHA-1: 9bea1d12eedf72d1ede075d42ddeece69148783f SHA-256: ef1cdc72902cd98ac71c9a1337c43dafd5f215a0b88a50ddd0f62d8ff44880c9
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The presence of external URI heuristics and compromised CMS upload links further supports the malicious nature of this document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://inwebjor.ru/uplcv?utm_term=dbz+dokkan+reddit
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/kakaboneduzuso.pdf
    • http://www.anieliasfx.com/uploads/textareas/file/67434832684.pdf
    • http://tcihk.com/userfiles/8029571528.pdf
    • http://kulturazebrak.cz/userfiles/varoxekokiruxotefuwi.pdf
    • http://ecme.site/2015/vat/upload/files/22363383902.pdf
    • http://netinflux.net/userfiles/file/19881349120.pdf
    • http://vertex-decor.com/userfiles/file/xugetidaxogisizolata.pdf
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16133de576aba2---5333477177.pdf
    • http://cutskytools.com/d/files/14594812217.pdf
    • https://aartipalette.com/userfiles/file/bokuzejuduselometur.pdf
    • http://olsztyntransportmedyczny.pl/userfiles/file/kinuk.pdf
    • https://urbanlivin.lu/userfiles/files/90138235109.pdf
    • http://colorfusion.us/admin/images/file/92251488180.pdf
    • https://basalyemek.com/ckfinder/userfiles/files/dizupufudulukuzidowu.pdf
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/161456b6e8bf3f---55550992733.pdf
    • https://m-astar.com/UserFiles/files/zajutavuzamefo.pdf
    • https://bisleriwheel.genefied.co/ckfinder/userfiles/files/79148908255.pdf
    • http://jedwines.com/cmsCart/upload/file/xitoxo.pdf
    • https://kapokcmassage.com/uploads/files/202109151159142056.pdf
    • https://anukulagrotech.com/userfiles/file/82309280298.pdf
    • https://www.hermanosvalerorecio.com/ckfinder/userfiles/files/kufeguxaxebusiv.pdf
    • http://eyela.kr/uploadfile/fckeditor/file/zawibofat.pdf
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/161392d5e95d7d---pabupiza.pdf
    • http://erainbowrealty.com/userfiles/file/xazuzudaxinima.pdf
    • http://adatarimhayvancilik.com/Images/Media/files/getisurukuxodogomap.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ba0a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBA0A 16792 bytes
font_01_sfnt_off0000d21c.bin
6f1b2a2074f710f0b431503137697d417f366dc5fd2ac460a4058129908e256b
pdf-font-stream PDF embedded font (sfnt) at offset 0xD21C 16792 bytes
font_02_sfnt_off0000fe0d.bin
01477c4e5bacabf415307eaf680fcab260b3c712a7841d9d36b08ae7591522f6
pdf-font-stream PDF embedded font (sfnt) at offset 0xFE0D 10320 bytes