Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4688b6141c17070…

MALICIOUS

PDF

85.9 KB Created: 2021-07-03 08:16:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b2609ecfc7620c045d4685fd866e399c SHA-1: 1ed99b159d4f73675e4e0a95cc390af7107ce31b SHA-256: f4688b6141c1707050454f39df4d3c5dc16d56d19d809118d2f2b965b42551c1
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress upload directories, suggesting it acts as a link farm to distribute further malware or phishing content. The presence of PDF_RANDOM_URL_LINK and PDF_SEO_DISPOSABLE_LINK_FARM heuristics confirms the nature of these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092f5fb8bf54---13505425587.pdf
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/1609f40604d06a---sisedatajudelenovoxuvep.pdf
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/160918d8078142---lawumulupajexuvomefot.pdf
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/5tbc7vg7ln44j3bnsi3j51f136/biruzanafojomifum.pdf
    • https://assurancemauricie.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a982f2634e2---woxabiveri.pdf
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a3de23be251---90457877127.pdf
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1608280c48a651---30594603564.pdf
    • http://lbhs1965.com/clients/6/6b/6bdd8f708684a1f547efbf97e1630fe5/File/37593538775.pdf
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/ipeo9jt9s9h139bnbrqdfap3gi/64620983843.pdf
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abd69b34fc9---vimusiwuzore.pdf
    • http://chicohigh1987.com/clients/47015/File/83451905251.pdf
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/dg9p7jmegd2ivpic2j65ml46hc/savutupirawuseporox.pdf
    • http://middlegeorgiacoinclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/160756d3563300---korudajopifutemupuxosepat.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/2phb2rr47i07td3r4gcsjibm83/tamapulofevafura.pdf
    • http://files.ibiza-ferien.de/file/vezofutajuvekovuvo.pdf
    • http://goldmustang.com/files/files/17370833922.pdf
    • http://iwish-cosmetics.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adf49daa30d---51502157391.pdf
    • http://tokyoto.pl/UserFiles/file/23845335784.pdf
    • https://www.isgs.org/wp-content/plugins/super-forms/uploads/php/files/4f1299f7e9ee7585c67e9f8dd352f4a4/dekugitafebokofeloritir.pdf
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/nnhcjd1s7ssgiob3vhjuqtinaa/41097298157.pdf
    • http://pcwest1980.com/clients/9/9b/9b13e9c1eb96aaf026ead536bb80a376/File/8068774464.pdf
    • http://alemotta.com/resources/original/file/vedowugoxesesoxomuzo.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=extracting+dna+from+banana+lab+answers
    • 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_off0000ea57.bin
79856a105f295db9623c4d2bd50ef815ad96682c0c09390aab8f7a6d319ab41a
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA57 11132 bytes
font_01_sfnt_off0001043a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1043A 16792 bytes
font_02_sfnt_off00011c4c.bin
f07520f919493ab2ee1e8c1ba6a567668117274870a33399aff52dce907ea0c0
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C4C 17456 bytes