Malicious PDF — malware analysis report

Static analysis result for SHA-256 516855bcafee1324…

MALICIOUS

PDF

84.2 KB Created: 2021-09-21 09:46:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 6bdb1c901757226d2c73778de8657bff SHA-1: f0aea9e981ef108cf6c714f92bc86b94a12daf59 SHA-256: 516855bcafee1324feb83a37397483e2aeb5da2db7d32b3a1189e2716d91e29a
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://webbsoil.com/home/webb/public_html/ckfinder/userfiles/files/didazu.pdf In PDF document text
    • https://karlholmbygg.se/UserFiles/files/98105890454.pdfIn PDF document text
    • https://kueapem.com/contents/files/88229439782.pdfIn PDF document text
    • http://z-him.ru/userfiles/file/zugozitolirevuludituve.pdfIn PDF document text
    • https://infotechb2blite.com/bot/ckfinder/uf/files/87222249356.pdfIn PDF document text
    • https://thucphamtruongxanh.com/Upload/files/savoniw.pdfIn PDF document text
    • http://constantcontinuity.com/membership/data/files/67237019685.pdfIn PDF document text
    • http://cana.vn/uploads/userfiles/file/zurumefujurefofatepapusoj.pdfIn PDF document text
    • http://highdeal.linkeo.net/ckfinder/userfiles/files/letokadatumufanivemavip.pdfIn PDF document text
    • http://gbfrjournal.org/pds/userfiles/files/95437757225.pdfIn PDF document text
    • https://vanchuyenduongsat.vn/upload/files/31485045245.pdfIn PDF document text
    • http://veiligheidssloten.nl/ckfinder/userfiles/files/sifovajaba.pdfIn PDF document text
    • http://minisadik-margaritka.ru/admin/ckfinder/userfiles/files/87997116131.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/161367a911b28b---tazejiv.pdfIn PDF document text
    • http://www.c-l-r-p.com/admin/ckfinder/userfiles/files/11711975491.pdfIn PDF document text
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f8532890a7---47820192125.pdfIn PDF document text
    • http://woodbridgeabw.com/uploads/files/87899276332.pdfIn PDF document text
    • https://shotclock.ca/wp-content/plugins/super-forms/uploads/php/files/2ab942bb7caafe24703f5451cf172696/60883124881.pdfIn PDF document text
    • http://yourhealthyanswer.com/ckfinder/userfiles/files/27397337379.pdfIn PDF document text
    • https://flomogroup.com/upload/files/ratojedazutufekasikiro.pdfIn PDF document text
    • https://www.jancsoalapitvany.hu/ckfinder/userfiles/files/zewipeg.pdfIn PDF document text
    • https://duocvinhkim.com/userfiles/file/38912660853.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=attack+on+titan+final+battle+apkPDF 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_off0000e28e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE28E 10416 bytes
SHA-256: 3153f2a58f336d1372442a2e4cf5713f18ef64a0b683a275c3339fe55153b11e
font_01_sfnt_off0000fa1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA1A 19088 bytes
SHA-256: 37e824d0382b0ab4e20408509f5b41a2854ef4f5acc5c09be8bb799da715ce60
font_02_sfnt_off00012b47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B47 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1