Malicious PDF — malware analysis report

Static analysis result for SHA-256 84185b21bcf75346…

MALICIOUS

PDF

86.5 KB Created: 2021-10-11 10:22:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: c4540382520533f246767738d7c8f7e8 SHA-1: 37f3f0b103b5bc79b68bbd8537c3aab9c4c56c69 SHA-256: 84185b21bcf75346cc71ccadae9d0e57d20a32a1f324db5bb35bbf1949a6009b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The ML classifier and ClamAV both flagged this PDF as malicious, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://laborke.ru/uplcv?utm_term=lamarr+of+boomtown PDF link annotation
    • http://dwallacelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/68995039224.pdfIn PDF document text
    • http://tieulongcopro.com/luutru/files/6032577535.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/b58ae0e03b71869fcd007c15fed03f73/50193759622.pdfIn PDF document text
    • http://knuhpharm.kr/userfiles/file/20210908011047.pdfIn PDF document text
    • http://tt-ural.su/admin/ckfinder/userfiles/files/xobubilijas.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/acf28f9db361a685e66bf14461b227ac/82109324202.pdfIn PDF document text
    • http://old.arcnet.org.tw/ckfinder/userfiles/files/nafadijibujaropijoguxovuj.pdfIn PDF document text
    • http://instit.ac/ckfinder/userfiles/files/63565356635.pdfIn PDF document text
    • http://siltherm.com/ckfinder/userfiles/files/taxamag.pdfIn PDF document text
    • https://lean-ds.com/upload/editor/file/woraludefiretexex.pdfIn PDF document text
    • http://clinicaveterinariaalbese.eu/userfiles/files/vivovirunisigex.pdfIn PDF document text
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1615f740f78a0c---lulozixukipiv.pdfIn PDF document text
    • http://hamdannepal.com/userfiles/file/xadudedivotufejedurami.pdfIn PDF document text
    • https://susta.vn/userfiles/file/7027977544.pdfIn PDF document text
    • http://hzkontejnery.cz/ckfinder/userfiles/files/52956328980.pdfIn PDF document text
    • https://youkuvpn.com/upload/files/doges.pdfIn PDF document text
    • https://weborder.cloud/userfiles/file///19646793433.pdfIn PDF document text
    • http://apple888.vn/luutru/files/lofasawosetupufesalux.pdfIn PDF document text
    • http://bavlas.lt/ckfinder/userfiles/files/51351850376.pdfIn PDF document text
    • http://rebizplus.com/userfiles/file/30624755117.pdfIn PDF document text
    • http://medob.org/SITE/files/editor/file/xamijomivigawodamavevem.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_off0000ecf7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECF7 10120 bytes
SHA-256: 2b2d74f1c8471bd406d65d1c5cdbbee32a5584e61ead6d26934bf35c1408eee8
font_01_sfnt_off00010390.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10390 19284 bytes
SHA-256: ca80fd491af959d50bf2c1326837d05bdbbbca4babcbb18410a1538c2f735e6e
font_02_sfnt_off00013620.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13620 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1