Malicious PDF — malware analysis report

Static analysis result for SHA-256 0841b630bf12ed27…

MALICIOUS

PDF

80.1 KB Created: 2021-09-17 08:49:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 967575b36a7eefeca57b2eef1192a9d8 SHA-1: 79588e702f83282436ab082e34c17edf0e7444ab SHA-256: 0841b630bf12ed2729dd5b59857bca99429a5c3bbd8a87d5b16c49570adbfc89
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The presence of multiple external URIs and link farm heuristics confirms the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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 https://synerhu.ru/uplcv?utm_term=windows+8.1+activator+key+free+download+64+bit PDF link annotation
    • http://aksaaydinlatma.com/img/editor/image/file/xoxomarowulurapadexarar.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1614020b2af50f---wedogazizejimejuta.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140f7ba2bd7a---pitosugofavew.pdfIn PDF document text
    • http://ultraljud.nu/bild/files/55074042075.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613decacc8d49---2624719812.pdfIn PDF document text
    • http://geometramaurotozzi.it/userfiles/files/gejovoxibes.pdfIn PDF document text
    • http://bocghedanang.com/media/ftp/file/vatedalofoxatojosixi.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/77548986914.pdfIn PDF document text
    • http://ulsantour.com/FileData/ckfinder/files/20210903_D9D765228E06E35A.pdfIn PDF document text
    • http://vimar.ua/userfiles/files/48039179566.pdfIn PDF document text
    • http://soldearenales.com/galeria/files/rusagetofiwu.pdfIn PDF document text
    • http://rent2day.ca/ci2/userfiles/files/49067201416.pdfIn PDF document text
    • https://corpusbg.com/files/fck/file/diweliroxarijumuve.pdfIn PDF document text
    • http://moscow-vernisage.com/files/files/88750766756.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/161413ed7313ca---91303258981.pdfIn PDF document text
    • http://podushka.by/files/files/rejoxi.pdfIn PDF document text
    • https://portugaliaimagyarok.com/ckfinder/userfiles/files/dapumabapelupebitibiba.pdfIn PDF document text
    • http://kramor.bg/userfiles/file/37574835022.pdfIn PDF document text
    • http://kidneytracker.com/ckfinder/userfiles/files/jinifun.pdfIn PDF document text
    • 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_off0000d38b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD38B 16816 bytes
SHA-256: 4b317d61ba8192b4d48ffe9facdc642d8abce5edffdb7ee596257d4922086be1
font_01_sfnt_off0000fef0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEF0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011707.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11707 11532 bytes
SHA-256: 40bf75d8aa3c1c5db9ce24137356353eb30709c881d2b007c218fdcab00b039a