Malicious PDF — malware analysis report

Static analysis result for SHA-256 2536771a23a05f2f…

MALICIOUS

PDF

75.2 KB Created: 2021-09-21 09:44:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: cd56eb4e725d3e4fc03d5848849471cc SHA-1: 2916aeb37055c03bd3b66cd549e4709759fa5a71 SHA-256: 2536771a23a05f2f7b00dad3ed425593e0ebe1ac771176723ae7841c638eb5d5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to various domains, some of which are hosted on compromised CMS uploads. While no scripts were extracted, the PDF structure and link farm behavior suggest an attempt to lure users to external sites, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://esoftland.com/userfiles/file/99125598967.pdf In PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/cd382e3f2cec98f846a0a3ed20db4eb2/22377901617.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/7b29e60cec6048953ed6673ffac06790/80562815833.pdfIn PDF document text
    • http://bjdfszwy.com/filespath/files/20210914002452.pdfIn PDF document text
    • http://holzweiss.at/49356329145.pdfIn PDF document text
    • http://kutscher-customs.de/gfx/userfiles/files/90517848904.pdfIn PDF document text
    • https://oancora.com/ckfinder/files/76817080754.pdfIn PDF document text
    • http://uat-tunisia.com/userfiles/file/94473897641.pdfIn PDF document text
    • http://am-assets.com/aom/magnolia/userfiles/file/42223470198.pdfIn PDF document text
    • http://ms-beauty.com/ckfinder/userfiles/files/87139982744.pdfIn PDF document text
    • http://s2ipower.com/survey/userfiles/files/76887440261.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132c38baa626---87844822451.pdfIn PDF document text
    • http://willbramephotography.com/63810295441.pdfIn PDF document text
    • https://stdtekstil.com/upload/ckfinder/files/71210908013.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161462106b2e95---bavewuwajuzebumotibi.pdfIn PDF document text
    • http://idealhca.com/admin/images/file/18668824190.pdfIn PDF document text
    • https://dolupin.com/calisma2/files/uploads/kuludopazuxitemuved.pdfIn PDF document text
    • http://navigator-nsk.ru/userfiles/file/xulirabagojopug.pdfIn PDF document text
    • https://xtrafitcoaching.com/www/images/files/jowovixojujitezikuxo.pdfIn PDF document text
    • https://kuni.ro/app/webroot/files/userfiles/files/84993654125.pdfIn PDF document text
    • http://barudan.hk/UploadFile/file/20210916033822173.pdfIn PDF document text
    • https://appvid.eus/userfiles/files/5337567884.pdfIn PDF document text
    • https://icrs-as.com/userfiles/file/xerudet.pdfIn PDF document text
    • https://www.nhabe.com.vn/ckfinder/userfiles/files/jiwuderozerivenutuwemu.pdfIn PDF document text
    • http://makairways.in/home/makairways2017/public_html/dowalumniusa/ckfinder/userfiles/files/44292688121.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=live+wallpaper+s9+plusPDF 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_off0000c32a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC32A 10300 bytes
SHA-256: e17ea9cf0647827511bfc1f242982c202eea7df91120d674c2256dea65e67d2a
font_01_sfnt_off0000da8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA8E 17052 bytes
SHA-256: 337f59383341083a3ca110d1350b992a1dbf1de72276ef2e1835b0567fef68c5
font_02_sfnt_off000106e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106E3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1