Malicious PDF — malware analysis report

Static analysis result for SHA-256 85a9a489ef09155d…

MALICIOUS

PDF

92.9 KB Created: 2021-07-30 09:47:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 88c31e3561fa95b3270075198821ebb6 SHA-1: ea8711561d924d741e24d263b03bc031e0f0fc75 SHA-256: 85a9a489ef09155d3208a37fa7be15875b2f829cc58ed5b600352dc31278ed7c
156 Risk Score

Malware Insights

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

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting a phishing or malware distribution scheme. The PDF document body was unreadable, but the presence of numerous links to potentially compromised sites strongly suggests an attack pattern involving directing users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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://dipinkrishna.com/wp-content/plugins/formcraft/file-upload/server/content/files/160722b541b936---nitefuziwipuk.pdf In PDF document text
    • http://omonetach.pl/foto/ilustracje/file/xeviwapop.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16083c5d079e07---vobiwenepopo.pdfIn PDF document text
    • http://wenxuezj.com/images/File/87176131066.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/160839674af98d---nibixokikage.pdfIn PDF document text
    • https://defaico.com/d/files/77779422342.pdfIn PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/1pta471ktll338so7ibfk4vp3a/37518881602.pdfIn PDF document text
    • https://navliecky.net/userfiles/file/telopamugogesijiful.pdfIn PDF document text
    • http://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc68cf4545b---tipifutuxu.pdfIn PDF document text
    • http://fincasotilloviejo.es/files/sotillo/_repo/file/27686095939.pdfIn PDF document text
    • http://divorce-difficile.fr/userfiles/file/92781168370.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160a6a382beb65---93952804872.pdfIn PDF document text
    • https://siphouse96.com/wp-content/plugins/super-forms/uploads/php/files/8e8242830aedf13b0150bdb64788cb7c/levemalajobonufuburag.pdfIn PDF document text
    • https://fastcomputer.vn/wp-content/plugins/super-forms/uploads/php/files/2e8eb26559faea798f2fd2ff3302a9c5/15336623116.pdfIn PDF document text
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/c574ea448b7d446e6191b3baae6716b4/moriboxegimalugunefinax.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c6bca0e79a4---sakofaxugigep.pdfIn PDF document text
    • http://hoshitorionline.com/uploads/files/jogofogekofobipetakiponos.pdfIn PDF document text
    • https://zlatartopalovic.rs//files/penulumedoge.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d9001a3a11c---nebolop.pdfIn PDF document text
    • https://alves.bg/ckfinder/userfiles/files/beboluzazofogixiva.pdfIn PDF document text
    • https://mudraconsultancy.com/uploads/files/20798845053.pdfIn PDF document text
    • https://ivanda-commerce.hr/userfiles/file/60819467643.pdfIn PDF document text
    • https://glycocalyx.nl/userfiles/image/file/wibuza.pdfIn PDF document text
    • http://fashioneducation.ru/userfiles/file/domadogorunejozetuxuvu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=how+much+does+it+cost+to+create+a+music+streaming+appPDF 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_off00010620.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10620 17296 bytes
SHA-256: 164e653b9e68e8a14493be9c6d3eac078c03b878cdda9f0637face68648d6246
font_01_sfnt_off00013363.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13363 11092 bytes
SHA-256: eae0c347e7dca7087a48a956d97bac4afb789c8edcb13e1bb7737b6636143b95
font_02_sfnt_off00014cea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14CEA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1