Malicious PDF — malware analysis report

Static analysis result for SHA-256 a21d76155ea8bd52…

MALICIOUS

PDF

115.1 KB Created: 2021-08-09 04:44:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 35e4a98b06709bdece6929581eb3f6b8 SHA-1: eb40fe9d7077fc724aa3a1ca9d6fdabc9ccc6c4e SHA-256: a21d76155ea8bd523c6849d058386c1f89066610508110811c578262c6fa1949
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to websites that appear to be compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond what the heuristics reveal.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/3mgtg7a2kbgpgks8vof15r25e8/15737929951.pdf In PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e975506f9cc---nexafelize.pdfIn PDF document text
    • https://earplighting.com/wp-content/plugins/super-forms/uploads/php/files/5d6a2889dc75a58120be2aaf37df78b5/dowuvakelevej.pdfIn PDF document text
    • https://www.pharmaright.ca/wp-content/plugins/super-forms/uploads/php/files/0rjm2ap16isr72q8ndgcj8ghhm/waxogeka.pdfIn PDF document text
    • http://abnicum.ru/files/file/getuwetaxis.pdfIn PDF document text
    • https://fuoriscena.eu/file/92347793447.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a326c97fba8---latanowuro.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160854aeb6860f---fugimodijozil.pdfIn PDF document text
    • http://abc-tel.ru/data/File/soponem.pdfIn PDF document text
    • https://kawanmto.net/contents//files/bawosuzowomiwiweja.pdfIn PDF document text
    • http://inter-travel.hu/_user/file/67543631876.pdfIn PDF document text
    • https://fmpride.com/wp-content/plugins/super-forms/uploads/php/files/51161416d28c4ff8f6efb499339e996d/36097579514.pdfIn PDF document text
    • http://sunnysideclassof64.com/clients/a/ac/acc4ccb49d7935ca36198347b895393e/File/sojolafuxugebevivijokiwaj.pdfIn PDF document text
    • http://bezagsecurity.cz/userfiles/33729079962.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/1606d8af175283---90477776026.pdfIn PDF document text
    • http://xn--dlek-5qa.com/admin/UserFiles/file/94682309078.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b7bfc3020a6---58346368162.pdfIn PDF document text
    • https://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/f740ec0c682fc1bcd51f88535b7ee132/21353153095.pdfIn PDF document text
    • https://harkakotony.hu/UserFiles/file/26015067957.pdfIn PDF document text
    • https://netron.pt/app/webroot/media/files/tazudusu.pdfIn PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a206c1174d5---fipimewolagusenovetafire.pdfIn PDF document text
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609176697154e---79530752427.pdfIn PDF document text
    • http://travisreunion.com/clients/1/1d/1d9c560ef9ee6310b862f4c9d288d7bd/File/soviv.pdfIn PDF document text
    • http://africareview.in/userfiles/file/74789850750.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=teenage+mutant+ninja+turtles+2003+episode+10PDF 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_off000158d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x158D0 19228 bytes
SHA-256: 5aadaa53759d95a87f811787467923efc17c325369c616a88c3852985d8d3e0a
font_01_sfnt_off0001896a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1896A 11396 bytes
SHA-256: 932bbe1d7242610472725a25ee1e6b9695d80774cbd919de1dc199edb8d80ca8
font_02_sfnt_off0001a415.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A415 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1