Malicious PDF — malware analysis report

Static analysis result for SHA-256 559b3f852eabb657…

MALICIOUS

PDF

71.0 KB Created: 2021-09-02 10:43:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 8be64eed7ca7ad07940db7a4e76273cd SHA-1: 506f46270768129943b10995b64b4fd512ae5ba9 SHA-256: 559b3f852eabb6574d4e16feddb881db03f5fe509f51c3d403269553d818cdd6
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and is identified as a link farm, with many links pointing to compromised WordPress installations. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware through these links.

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://cructi.ru/uplcv?utm_term=math+answers+textbook PDF link annotation
    • http://spamsmsgiare.com/media/ftp/file/welerefevawi.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c04239466e6---tonutobarez.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/1b16c5cade6a1e0ae79495500d807eb0/sapinesobatijujiwoxepodod.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/e738acf8976f99aa58a69d845d241d56/wapavilimafikuwek.pdfIn PDF document text
    • https://saksisan.com/upload/ckfinder/files/69849384581.pdfIn PDF document text
    • http://gioiacompany.net/images/upload/file/nozuzogemi.pdfIn PDF document text
    • http://mattstergamer.com/wp-content/plugins/super-forms/uploads/php/files/6n8tb114lnph432tohllqntro4/68959898080.pdfIn PDF document text
    • http://chinhsuasolieu.com/media/files/56707484950.pdfIn PDF document text
    • https://olgapopovaphoto.com/wp-content/plugins/super-forms/uploads/php/files/790284eb5e388eee007fd4e7212e6c66/92993501571.pdfIn PDF document text
    • http://unewstoday.com/task/userimages/file/6213504695.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0c6299bb63---86169797307.pdfIn PDF document text
    • https://rosewoodcity.org/nbloom/fckuploads/file/monijanutaf.pdfIn PDF document text
    • http://servmed.net/userfiles/file/57623654866.pdfIn PDF document text
    • http://gwardiajuvenia.pl/zdjecia/fck/file/duvifaseze.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/8486ff7841ff31f9d566caae0b7adbc6/tewin.pdfIn PDF document text
    • http://feldbach-tourismus.at/files/44598960087.pdfIn PDF document text
    • https://www.mii.net/wp-content/plugins/super-forms/uploads/php/files/abe7cfa9fac61372df7db67950c8edfd/sapivuruneletimojoli.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/5e0ad5f10d59b3e97ef9b5451ed2ab06/xadakux.pdfIn PDF document text
    • http://www.assignproject.com/wp-content/plugins/formcraft/file-upload/server/content/files/160813ab9422b3---joxafezonekunewegulamif.pdfIn PDF document text
    • https://defi128.com/userfiles/files/13549672811.pdfIn PDF document text
    • http://fitviewer.biz/files/file/zoxusi.pdfIn PDF document text
    • http://www.zywawiara.pl/pliki/zizotatizakoluwobojo.pdfIn PDF document text
    • http://donghocasiochinhhang.net/uploads/userfiles/file/32522053172.pdfIn PDF document text
    • http://pechati-piter.ru/userfiles/file/fubinirilapilisamutiv.pdfIn PDF document text
    • https://sadex.pl/fck/file/mesipisuzobu.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_off0000b8a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8A7 10480 bytes
SHA-256: 9335b3e351c609a07ccc85fb594a62fd2373009082486884f1113899e46db3c4
font_01_sfnt_off0000d085.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD085 15036 bytes
SHA-256: c18bf0faa51e251436652717ea22aaf7a8217dda3a3496470c441485648f6ddf
font_02_sfnt_off0000f69b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF69B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1