Malicious PDF — malware analysis report

Static analysis result for SHA-256 b10ef073c0467957…

MALICIOUS

PDF

77.2 KB Created: 2021-08-30 06:46:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 41a669c8cc577e7e846ea624198ee197 SHA-1: 3a6171ee7add3af72f6474932b4531e0936944cc SHA-256: b10ef073c04679573816f70a7b12e5da4c48babc6092a1de3f42a13204927e00
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. The embedded URLs, such as https://laborke.ru/uplcv?utm_term=early+superficial+spreading+melanoma, are likely used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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://laborke.ru/uplcv?utm_term=early+superficial+spreading+melanoma PDF link annotation
    • http://hillsdalehorseboarding.com/ckfinder/userfiles/files/xulor.pdfIn PDF document text
    • http://home-hj.com/up_photo/file/roluturavawomanegapupigad.pdfIn PDF document text
    • http://zentrumok.com/userfile/files/38573990053.pdfIn PDF document text
    • http://2446665a.ru/ckfinder/userfiles/files/fazinagokuvapemoxug.pdfIn PDF document text
    • http://phuwangnam.com/user_file/file/kojuvawumibo.pdfIn PDF document text
    • https://yukkumpulgroup2.com/contents//files/42596918523.pdfIn PDF document text
    • http://jorkurojus.com/userfiles/file/zufuxilojoginop.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/161079cd1232c4---gudezagumu.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/kotikopenudozitigoz.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/16080650265b04---dulubosasijebu.pdfIn PDF document text
    • http://unipsyclinic.com/userfiles/file/20210509173556.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/krq5fpqopicbg0ep9rlov48k6n/82100031758.pdfIn PDF document text
    • http://domeinbeverdonk.be/assets/files/file/vunatinenupadevizakuvanu.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/1608e6ca0b87fa---dafikepiji.pdfIn PDF document text
    • http://ever0036.com/assets/uploads/ckedit/files/20210620011854.pdfIn PDF document text
    • http://michardardillier.com/ckfinder/userfiles/files/28447128573.pdfIn PDF document text
    • https://ecotranslation.ca/upload/editor/file/38365456475.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1606c833d0c2ba---87945472409.pdfIn PDF document text
    • http://heydarbaba.org/resimler/files/xuxiloxuxafojuvajebuj.pdfIn PDF document text
    • http://stillwaterponies83.com/clients/74660/File/50746970318.pdfIn PDF document text
    • https://villamishkan.com/310renonew/front/images/files/8783013863.pdfIn PDF document text
    • https://aydin-elektrik.com/resimler/files/livivisuvonekezikipokofa.pdfIn PDF document text
    • https://wfca-czech.cz/temp/userfiles/files/95206850112.pdfIn PDF document text
    • https://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/f3d9ebf1664d97b1d460371683069636/60544381065.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_off0000c900.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC900 17072 bytes
SHA-256: 4a2f387e6b1c8c98a727d72f2e5d9ce563b196d0856b1064ffcd78b4b2e9093c
font_01_sfnt_off0000f4d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4D3 11060 bytes
SHA-256: 4e25c1478d3d195556739635e1db041e5f9e1c5720fb31ca38061b2537f560d5
font_02_sfnt_off00010e55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E55 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1