Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8d4b876532e0588…

MALICIOUS

PDF

86.2 KB Created: 2021-06-29 07:47:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8c5a53886a9dbe045574bacc8fc021a3 SHA-1: 6a63f0b7a8d4ed49407a9613cfbc130566af2e70 SHA-256: b8d4b876532e05885c4080d456cd1d3af1c6176d76c74205c38bad43766a2539
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

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 CMS upload storage, specifically WordPress instances. These links are likely intended to host malicious content or redirect users to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7b80b1193---jeletosisoxe.pdf
    • http://odpadykj.cz/UserFiles/File/65999288943.pdf
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/438c40b4fb0232315476e4c53f013c99/zirurezezuwevewupideloxef.pdf
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/9gu9ra8oo6u7uv74isptfmq1l8/61844104581.pdf
    • http://staples1981.com/clients/b/ba/ba027a536d51c1d997ee76cae6dc9017/File/zopet.pdf
    • http://bakoca.hu/files/file/57272200365.pdf
    • http://ourdesign.hk/ckfinder/userfiles/files/21156361981.pdf
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160890587d78c1---89045512460.pdf
    • https://smilepath.com.au/wp-content/plugins/super-forms/uploads/php/files/4ff2348d51fe2ee14bf8c51eb9591124/33485998853.pdf
    • https://cor.org.ar/wp-content/plugins/super-forms/uploads/php/files/5nr97l6hrui00sunp0nbt57ijh/piwulafa.pdf
    • https://x-software.cz/data/file/30114205381.pdf
    • https://beldaoyun.com/calisma2/files/uploads/87767776924.pdf
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/160c77b176a154---78922802351.pdf
    • https://nowbali.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/1609eea06090ae---19784379608.pdf
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078a0bc95fcc---80263338969.pdf
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608f6fda65946---judeb.pdf
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab63cc1f4d3---nixigo.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c34e99bb9fe---xiverivajuwinelomitibuko.pdf
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606f0545e18d0---nemijeme.pdf
    • http://targhevaticane.it/userfiles/files/15468345165.pdf
    • https://altbuket.ru/files/11855826856.pdf
    • https://audreyheselmans.com/_files/file/pivejobul.pdf
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/9fed65bf143570c608cff368400b0d9b/mevoruteb.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=paper+tearing+meaning
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eb31.bin
1bbf26c7666a2e62cdd8c6d8600c3cbc6dfad29b9071fbc9227bc116977b3709
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB31 10264 bytes
font_01_sfnt_off0001023c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1023C 16792 bytes
font_02_sfnt_off00011a4e.bin
345d24e1cb6a648904ea4fd537f574d91577de1bb24d8ec8ced8d3e6fb78b796
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A4E 18792 bytes