Malicious PDF — malware analysis report

Static analysis result for SHA-256 98834391d9b9aca5…

MALICIOUS

PDF

89.4 KB Created: 2021-07-08 12:04:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7d88f9dc67f42c668f203562b203b4ad SHA-1: 500e652e7d2133513a6486bd9647757bbed20d0a SHA-256: 98834391d9b9aca539b970a629056c9e16862c05b2100c928bd2328b553396c1
156 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. The heuristics reveal it functions as a link farm, with numerous embedded URLs pointing to compromised websites and potentially disposable hosting. These links are likely intended to lure users to phishing sites or download further malware, aligning with a common phishing or malware distribution attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://synerhu.ru/uplcv?utm_term=pork+chops+with+onion+soup+mix+gravy
    • https://www.amiunaorchestra.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a368c310f24---70250304167.pdf
    • http://goref.ru/files/file/wimudil.pdf
    • https://valserve.in/web/k/main_admin/ckfinder/userfiles/files/67522381608.pdf
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a56ee2560d9---57675934323.pdf
    • http://scheiden-maassluis.nl/uploads//file/desovumop.pdf
    • http://itkaufmann.com/images/fckimages/file/19641064205.pdf
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/16092ea6164602---43846301992.pdf
    • https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/nhcpbplvdiukd1ukjjhtgqndh2/zerigo.pdf
    • http://quangcaosms.org/media/ftp/file/porumipukot.pdf
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/41b15e364cb17dce52ab53e0098f9580/39666608273.pdf
    • https://mls.lighting/wp-content/plugins/super-forms/uploads/php/files/fd896c2b8394481761d71e9f21b67b28/25515402488.pdf
    • http://alsumiri.net/wp-content/plugins/super-forms/uploads/php/files/c5e407746f4d8b8bdc1aacf538111cdb/rodizokoxod.pdf
    • https://semut73.com/contents//files/gowuzekobif.pdf
    • https://alamansyria.com/userfiles/file/janazixegekazeni.pdf
    • http://beiwendq.com/userfiles/file/tikirutanifog.pdf
    • https://bringem.de/wp-content/plugins/super-forms/uploads/php/files/0ecdae1e7e2bb1600b0d89d36cd3da13/tixabemukimul.pdf
    • http://maility.pl/_ADRESuserfiles/file/dobejuxo.pdf
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/m0r4lsafdckpo64fv07qmpav4t/foluponagaxifepejatadipus.pdf
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160aac1862ed2f---walubevusemisisutu.pdf
    • https://vestol.bg/files/file/togalosazonitimu.pdf
    • http://sns.hu/_user/file/78269698340.pdf
    • https://www.expoagrogto.com/wp-content/plugins/super-forms/uploads/php/files/3cg5k2d40liptkck7fpdbta8b3/tizixexilosunemad.pdf
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/7fb371098f08cb86cdedff6d46733951/divel.pdf
    • http://northcity.rs/slike/files/65759350109.pdf
    • http://jjmcp.jp/userfiles/Image/file/nepalewabipo.pdf
    • http://westmoorclassof1965.com/clients/5/52/52ec68f2b927accf75267cb07bfcc891/File/33634676447.pdf
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/16077563360fb1---4262664069.pdf
    • https://babamore.com/upload/ckfinder_temp/files/20210530034405.pdf
    • 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_off0000f881.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF881 16792 bytes
font_01_sfnt_off00011093.bin
8aa44e9cdee1677a258542ba77fabe4026c519af660b481da9ce5d512bc57576
pdf-font-stream PDF embedded font (sfnt) at offset 0x11093 17472 bytes
font_02_sfnt_off00013d98.bin
1d2b955d0fcba56900639bc1505571f6d337a4a0300cc05b666ec588702f9191
pdf-font-stream PDF embedded font (sfnt) at offset 0x13D98 11204 bytes