Malicious PDF — malware analysis report

Static analysis result for SHA-256 a76f9860ac4a3b1d…

MALICIOUS

PDF

81.1 KB Created: 2021-09-12 04:49:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: e5394eb5f0a5285b4e71a7c6d4136343 SHA-1: 35708f65fbfa750009df2e9bb5a58ca323ead38c SHA-256: a76f9860ac4a3b1da3d94b1951d0afe365bccc4558eaad3157ba581206d1431a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains numerous embedded URLs pointing to various domains, many of which appear to be compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and unreadable, but the presence of external URIs and link farm heuristics strongly indicates a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://synerhu.ru/uplcv?utm_term=how+to+fix+message+memory+full+on+android PDF link annotation
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/7ed1894936eed34ba3be0736e7b025ff/nivolewofafusuxeko.pdfIn PDF document text
    • https://webmenuplus.com/images/file/rifukegap.pdfIn PDF document text
    • https://pokereshop.cz/data/file/91307767768.pdfIn PDF document text
    • https://homeuu.biz/upload/ckeditor/pages/files/83435723524.pdfIn PDF document text
    • https://hglobaltourb2c.com/FileData/ckfinder/files/20210908_20BECA7E0FC9DAF1.pdfIn PDF document text
    • http://waterlootour.com/FileData/ckfinder/files/20210909_10469A515AF80D74.pdfIn PDF document text
    • http://aardbeienfeesten.nl/uploadimages/files/vagerite.pdfIn PDF document text
    • https://nnt52.ru/userfiles/file/fajesiroderefek.pdfIn PDF document text
    • http://gandolfiarchitetti.com/userfiles/files/740483769.pdfIn PDF document text
    • https://goodmix-psc.com/userfiles/files/3160258632.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/161348429353cf---sudezoje.pdfIn PDF document text
    • http://sicompk.com/survey/userfiles/files/wubip.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/161313f7e565a4---29467156270.pdfIn PDF document text
    • https://greenlandpark.com/uploads/files/puminolovedawa.pdfIn PDF document text
    • http://cl-pub.com/files/files/sapuvimotuf.pdfIn PDF document text
    • https://cihangirhotel.com/upload/ckfinder/files/22631035130.pdfIn PDF document text
    • http://motovelo-nmsk.ru/userfiles/file/rizejejazez.pdfIn PDF document text
    • http://qianlong99.org/ckfinder/userfiles/files/denedajula.pdfIn PDF document text
    • https://jdrum-music.com/uploads/ckfiles/files/56872939574.pdfIn PDF document text
    • http://tdsns.ru/userfiles/file/94171504322.pdfIn PDF document text
    • http://greenglobepms.com/uploads/52988502503.pdfIn PDF document text
    • http://globalbizkorea.com/userData/board/file/24079782061.pdfIn PDF document text
    • https://cremyco.com/app/webroot/docs/file/xosud.pdfIn PDF document text
    • https://kemxoi.vn/app/webroot/files/images/pages/files/56218410716.pdfIn PDF document text
    • http://pegasomeeting.medcoast.net/ckfinder/userfiles/files/xakelefusazegagu.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_off0000d665.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD665 17672 bytes
SHA-256: 8a246887fe149f6b0c72f2af68b38d72cc1a8a5186cdb537bff9ecd396f676fe
font_01_sfnt_off000104c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104C8 11092 bytes
SHA-256: 184fbc86c449f1ee5cc78054efeddf798ff950ab6406679e2176ed024d52dc6c
font_02_sfnt_off00011e79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E79 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1