Malicious PDF — malware analysis report

Static analysis result for SHA-256 51d80c758dc165f8…

MALICIOUS

PDF

87.1 KB Created: 2021-06-30 05:51:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: f8ed857b46acac653cb8756d910adcf6 SHA-1: c97421feffb6bb919121cf5376bda6d85f16a889 SHA-256: 51d80c758dc165f8519b1b85cae4a7e97eaf6f0b2e73704b38e1f57744a33691
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised WordPress upload storage, with numerous distinct hosts and disposable domains. The embedded URLs suggest a phishing or malware distribution attempt, likely initiated by a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/li7g10ppor8t6piv4n78cfgetb/14881080565.pdf In PDF document text
    • https://nailseasupportgroup.com/wp-content/plugins/super-forms/uploads/php/files/d8a743b9b3ba1b5826eb6a0a2d1ec05d/labejinipixid.pdfIn PDF document text
    • https://www.herewardcarpets.co.uk/wp-content/plugins/super-forms/uploads/php/files/shd07o8aooatd39o9ilguaqgm4/kupabuxokebepi.pdfIn PDF document text
    • http://hattingtoemrerogsnedker.dk/userfiles/file/digepuzaxojokidixip.pdfIn PDF document text
    • http://innotec-industrie.be/userfiles/file/29178606372.pdfIn PDF document text
    • http://nadiadsa.org/userfiles/file/loralome.pdfIn PDF document text
    • http://fongyoskert.hu/userfiles/files/zilurosibedawavonuk.pdfIn PDF document text
    • https://militarynetwork.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16070b54f9e283---gasija.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160cd5e7e4c421---kegivepunerojaleg.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/a15101b297e6716c25455c0fc42eff8d/zaporexusaf.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608d78065abc6---jajasune.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608467a44a471---45471821480.pdfIn PDF document text
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/aengdn1rd67ff8foen5lfvsqi5/99505496081.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/fabc3a99d4c204f1af7afd1001551a70/56523567126.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080cbdb7a3f8---27221746504.pdfIn PDF document text
    • http://xn----8sbnbd9chja.xn--p1ai/userfiles/file/74009050882.pdfIn PDF document text
    • https://samiznojmo.cz/wp-content/plugins/super-forms/uploads/php/files/520d385604905fcfc6a214b2612aabc8/92696927324.pdfIn PDF document text
    • http://skyline1968.com/clients/74864/File/bagifevijonapivab.pdfIn PDF document text
    • https://regeneracion-capilar.com/wp-content/plugins/super-forms/uploads/php/files/536485c8b727190d78d6f07fd6a3fc57/52848961145.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0673d9fdba---86228284130.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/9l8k83m5butqeak6fh4bgtj9m6/jumixebitexun.pdfIn PDF document text
    • http://ceskylakros.cz/userfiles/file/vijefoxokujifodigijexofo.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a0390a9b8c0---63251542789.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6ec006bbbc---10451530364.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609bfaf1eb8eb---53964271195.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/12f1d1f120146261348248ec88a5fa40/disejonobiw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=arbitrary+meaning+in+malayalamPDF 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_off0000eb2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB2F 20280 bytes
SHA-256: 72c636a996199e27778cedc7fd96fa1c62cafdf58ed36e533b5cf0bb7206be3a
font_01_sfnt_off00011f54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F54 10400 bytes
SHA-256: ef6b4b5cd2375761f0a6bca98379beb134a02a34d0a2513659ec7066c7aa2ccb
font_02_sfnt_off000136e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1