Malicious PDF — malware analysis report

Static analysis result for SHA-256 3ab5851884311dbd…

MALICIOUS

PDF

83.4 KB Created: 2021-06-25 12:33:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: d319b32d50c8946357a8075f72d490e6 SHA-1: 26c37b0ed290a851d3c1c50bd3c98e42e8e3d525 SHA-256: 3ab5851884311dbd44159d66b06e7e8c4d96c3f10e72653103fce75cf31921ee
156 Risk Score

Malware Insights

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

The PDF was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV detecting it as a phishing trojan. The document contains numerous links pointing to compromised WordPress sites and disposable domains, suggesting a phishing or malware distribution campaign. No scripts were extracted, and the document body was unreadable, but the link farm structure is a strong indicator of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://crewmak.ru/uplcv?utm_term=how+to+reduce+size+of+pdf+on+mac+without+losing+quality PDF link annotation
    • http://aihyang.com/userfiles/file/gomesex.pdfIn PDF document text
    • http://fapannimario.it/userfiles/files/divedumisiga.pdfIn PDF document text
    • https://higher-reason.com/wp-content/plugins/super-forms/uploads/php/files/6urbdos1tlr8l8u287vj1ea88g/1293808662.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bede2398aa3---17892090436.pdfIn PDF document text
    • http://integrotech.com/zdjecia/file/mesekonudowub.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607b224be50f4---riwaferiluwukovifu.pdfIn PDF document text
    • http://iburgisidimarsala.eu/userfiles/files/rifaburiduzimavom.pdfIn PDF document text
    • http://gangwonbnb.com/FileData/ckfinder/files/20210618_D47185C985D8EE95.pdfIn PDF document text
    • http://hysansam.com/fckeditor/userfiles/image/gonirizazewatanuximamit.pdfIn PDF document text
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088f58c9f4c3---49406239360.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/1abhbr9ro80m598i5pbecdvonb/4019774298.pdfIn PDF document text
    • https://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/8e07c20d7361727e84a8e72c18dfe84c/59205304366.pdfIn PDF document text
    • https://www.spreefahrten-berlin.de/wp-content/plugins/super-forms/uploads/php/files/20m735epcj25q441tf3e5ekt2t/51891267436.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/2e40e4fb8d8283773b181984d018c42d/wefifetopiborexurakimufuk.pdfIn PDF document text
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7a1e95990---83041868192.pdfIn PDF document text
    • 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_off0000df0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF0B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f71d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF71D 17088 bytes
SHA-256: 37a6d7f31b4a131f77f9a7c8656c80b964192ddc207a3d4bf749d1aff4d37d3d
font_02_sfnt_off000123c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123C4 11564 bytes
SHA-256: b180a8854f2918a81b40c6651ef1f48acadfea90355722801bc96fcf44cb01ea