Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9bc6358a00a5622…

MALICIOUS

PDF

82.4 KB Created: 2021-09-17 02:33:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: aef3f9525fb1382f3b1ba48031fd32ee SHA-1: 65c2df05b492cd204d5c620f2369c5bd92b07541 SHA-256: b9bc6358a00a56222d48bebcc8187e67cf04ccc492aa4ff8f564301ea47538f9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress uploads and disposable hosting, suggesting it's used to redirect users to malicious sites. The PDF structure itself does not contain readable content, but the associated URLs are the primary indicators of its attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ede085ed77---fupod.pdf In PDF document text
    • https://tefen67.com/userfiles/files/gugewonuwa.pdfIn PDF document text
    • https://beaszemin.com/files/2732433765.pdfIn PDF document text
    • http://ammk.sk/userfiles/file/66346893045.pdfIn PDF document text
    • http://millionsdiscount.com/mo_images/files/tubikodaxapefoxenu.pdfIn PDF document text
    • http://cerescommoditiesltd.com/Images_upload/files/begujobotogifisetexusa.pdfIn PDF document text
    • https://total-sport.pl/img/upload/files/mejonanuw.pdfIn PDF document text
    • https://gilboamedia.com/userfiles/file/diwarojuvivoxopoxo.pdfIn PDF document text
    • http://solarhomepage.ch/fckeditor/editor/images/file/puguxufilimuvurojuxap.pdfIn PDF document text
    • http://nhatrangpalace.vn/app/webroot/upload/files/pijoreme.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613c1471030e6---10096681483.pdfIn PDF document text
    • http://nhuaduongnhapkhauaz.info/upload/files/wefifeninepadofidoruri.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16133441c4d880---47372899021.pdfIn PDF document text
    • https://hotararicedo.ro/files/files/1975374264.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613f5b65f2029---42201513390.pdfIn PDF document text
    • http://cmtdental.com/upload/ckimg/files/2679669334.pdfIn PDF document text
    • http://aerotherminsulation.com/userfiles/file/wafamozewabegu.pdfIn PDF document text
    • http://hiredriver.com/uploads/assets/files/nalimokop.pdfIn PDF document text
    • https://duvarkagidierzincan.com/userfiles/file/nufezigixeguripowowevo.pdfIn PDF document text
    • https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/t6qh9fpqqpnigof3v2j91dt533/woladerev.pdfIn PDF document text
    • http://thuduchouse.vn/pics/file/gimojukobodatetanurusadi.pdfIn PDF document text
    • http://ck-kutnahora.cz/gais/image/file/fudajebidat.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/161409b267d6ae---81713179276.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=where+is+the+voice+recorder+on+my+androidPDF 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_off0000de3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE3A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f651.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF651 10760 bytes
SHA-256: 2e323c3506fbc176af6272a0f3c11738471b59b3e3185b04270ee1090e70ef24
font_02_sfnt_off00010efb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EFB 17364 bytes
SHA-256: 10ff2dbb7c8499efbfce02ae365ef9202153f295797dee5b109cf539ebdce8d4