Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac4ba1b5cb2907ce…

MALICIOUS

PDF

92.1 KB Created: 2021-07-19 07:04:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: d60cc88572f9865f51aac5538134dd56 SHA-1: dc14696be267d4da3a73020baf26c887ef6e2b56 SHA-256: ac4ba1b5cb2907cea51ae4b0a9ddf91666c07161dfdf529a652898a0c69c505a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised or disposable hosting domains, suggesting a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The document body is heavily obfuscated and unreadable, but the heuristic firings confirm the presence of a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://suprizpin.com/calisma2/files/uploads/tuxur.pdf In PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d24432b1a1.pdfIn PDF document text
    • http://skncn.com/u/files/pozaborexupupog.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8e5a6b12a---18015793390.pdfIn PDF document text
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d0afc08329---samuzavefarufaxojo.pdfIn PDF document text
    • http://rc-modeller.se/images/file///fikoxifelalepabefizefaso.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1e02b1803c---pututapuwupasegaketemik.pdfIn PDF document text
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/b88210f36db10c02c9d6e25833873115/tabawuwulur.pdfIn PDF document text
    • http://elijasprojekts.lvfiles/file/77016600962.pdfIn PDF document text
    • http://robertsrucker.com/clients/7/7f/7f5ecd1287ec2152c36a7dc1808edcbf/File/36832091890.pdfIn PDF document text
    • http://firmykominkowe.pl/Obrazki/edytor/file/23038266257.pdfIn PDF document text
    • http://antonioruizabogados.es/userfiles/file/71714469267.pdfIn PDF document text
    • http://qiangka.com/ckfinder/userfiles/files/kelutipibatemategovi.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/2b6hkilp7qk57ncn9jpounj0va/67605490618.pdfIn PDF document text
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/9c99312580ce6238914d67ef11a5ac2c/moranafagojudefo.pdfIn PDF document text
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/38855a721d707ea21b641eb18e563691/47173177173.pdfIn PDF document text
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/fe318d237e7d9d9d50e636afcb9c5ab9/66875323384.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160978df513829---lebifovorotedefavu.pdfIn PDF document text
    • http://ahkjt.com/upfile/file/susozudumilekaro.pdfIn PDF document text
    • http://ototavandosemesi.com/resimler/file/94293907006.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/jifeserobogigogoroxasaja.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16082637a84906---60379266251.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/76686181653.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b2df461a61---47102123485.pdfIn PDF document text
    • https://actor-conseil.com/files/file/39580782550.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=seven+more+languages+in+seven+weeks+pdfPDF 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_off00010285.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10285 11164 bytes
SHA-256: 5b7fe4e0562fd393349da2b84e7d81f6870df1850a914a4bf2d12bfeb89cd073
font_01_sfnt_off00011c6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C6F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013481.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13481 17116 bytes
SHA-256: 7de0fa9d23b3b2f702e413f10de0dc9a63e8e02c6f57ede4a5a2ae3fcffd11e8