Malicious PDF — malware analysis report

Static analysis result for SHA-256 259da05f992a19c9…

MALICIOUS

PDF

81.9 KB Created: 2021-09-17 08:22:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6de878dffc2d4d4496edd546464573dc SHA-1: f8c987ded7e6aab91460cc37d4df11947359b90e SHA-256: 259da05f992a19c930d3cc24d5293f3e25ae9fcd7154e3f6eb3f02d84022eedd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised websites or disposable hosting, indicating a link farm designed to lure users to malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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=toefl+independent+writing+template+pdf PDF link annotation
    • https://goodluckfishing.com/ckfinder/userfiles/files/fafikolepepinizewak.pdfIn PDF document text
    • http://ace-pharm.com/upload/files/26371519097.pdfIn PDF document text
    • https://bayihoki99.com/contents/files/fofutosujem.pdfIn PDF document text
    • http://www.saito-ken.jp/userdata/file/fatowikujipuwid.pdfIn PDF document text
    • https://saikekanglun.com/filespath/files/20210917085617.pdfIn PDF document text
    • https://bosingels.nl/ckfinder/userfiles/files/26598349386.pdfIn PDF document text
    • http://lachina.cn/upload/file/43803653228.pdfIn PDF document text
    • http://nousgarage.com/userfiles/file/femabuxef.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142100e8df60---58946418975.pdfIn PDF document text
    • https://whitesal.com/data/images/file/5196_20210910070155.pdfIn PDF document text
    • https://holocaustresearch.pl/nowy/photo/file/tuvatotidarugad.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613385017330c---lagar.pdfIn PDF document text
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/161320510e2bca---8675545327.pdfIn PDF document text
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131d2eea182b---98883268450.pdfIn PDF document text
    • https://galerieportelouise.be/userfiles/files/49061414210.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/6cae2d8aaff67e35bdfc7144b72da8bc/13577594053.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614131f1b7cf1---84690477621.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144110f0d35f---wevovojoguzoborafujix.pdfIn PDF document text
    • http://abyss.sk/userfiles/file/22862958367.pdfIn PDF document text
    • https://kermoulin.com/userfiles/file/roruta.pdfIn PDF document text
    • https://alemarferries.alemarsnp.gr/ckfinder/userfiles/files/rizud.pdfIn PDF document text
    • https://wonwon.taipei/photo/file/20701422142.pdfIn PDF document text
    • http://csc-vietnam.vn/uploads/userfiles/file/14560516341.pdfIn PDF document text
    • http://heninrealty.com/userfiles/files/rekenedotobevip.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_off0000da8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA8E 18236 bytes
SHA-256: c8906524aa925cc8f2b4124b6fbd7fd4c5bc84923625fb09c64cf7298f87e727
font_01_sfnt_off00010962.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10962 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012179.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12179 10720 bytes
SHA-256: 1405353ca8416daef95a218fec29c603156ff79def8db4759d2cba01b5cfea81