Malicious PDF — malware analysis report

Static analysis result for SHA-256 a53604d2467fa0dc…

MALICIOUS

PDF

71.1 KB Created: 2021-09-29 03:53:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7d53ef021c22d8c9cd1786400df6d3c7 SHA-1: f6ab162ab150d74775de455ecf52784ef2c10bf7 SHA-256: a53604d2467fa0dc7f248261d0cdeb790166abbc8d78942b5a3e50480891d0fa
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous embedded URLs that point to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of these URLs and the overall structure indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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://crewmak.ru/uplcv?utm_term=fpse+for+android+devices+free+download
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136021f481a0---91750912523.pdf
    • http://myappartement.de/web/editor/files/vuzotudidoz.pdf
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/16149e4525aac2---tepexononunudatiwofapobu.pdf
    • https://promobryansk.ru/userfiles/files/komutijikod.pdf
    • http://www.armstrongre.com/files/files/pedoxetanedabogesu.pdf
    • http://bimbrlata.cz/UserFiles/File/vigazexugudadevaxobada.pdf
    • http://ls12368.com/userfiles/file/karogidinuf.pdf
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/3ee15d8b4cd118ff993289c54e27554a/nuruwoduparumixoba.pdf
    • https://inchirieriavioane.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16136f9017c96e---40366180950.pdf
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1613d13cc55aa5---30884554822.pdf
    • https://cesiedizioni.com/userfiles/file/sisavujadifoja.pdf
    • http://xn--80aab8aioy.xn--p1ai/userfiles/file/dobajit.pdf
    • http://aal.tw/uploads/htmlupload/files/ratekogisojajag.pdf
    • http://bodegaadrover.com/userfiles/imagenes/27255646726.pdf
    • http://grgct.com/ckfinder/userfiles/files/69912273891.pdf
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/b0e27a7fca3536bfdda1b8861931ac6a/65364127664.pdf
    • http://maschimaurizio.it/userfiles/files/sadonas.pdf
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614f5532542d1---92915708440.pdf
    • http://naszymsladem.pl/upload/file/78310316030.pdf
    • https://eventpro-kontraktorpameran.com/uploaded/files/51116465481.pdf
    • http://sarljarry.fr/userfiles/file/mumobepe.pdf
    • http://peknanevesta.sk/media/file/dudegomanabibowajep.pdf
    • http://maidichike.com/upload/files/lakawuki.pdf
    • http://studio5r.com/userfiles/files/talovujeferibodezuf.pdf
    • https://nstyapi.com/resimler/files/72731672127.pdf
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/de255870e74f4e34514c2d821a3d888f/36133022974.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_off0000b5f6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB5F6 16792 bytes
font_01_sfnt_off0000ce08.bin
bcec26b96e1fdbff756b530c34e3021662bf0d79abc70985bd6df8b860ba7f41
pdf-font-stream PDF embedded font (sfnt) at offset 0xCE08 14932 bytes
font_02_sfnt_off0000f3ef.bin
d47635c0d101d8324baff3bcfcdae1050c73b829804303f68f3b1a4ce7e2a485
pdf-font-stream PDF embedded font (sfnt) at offset 0xF3EF 10644 bytes