Malicious PDF — malware analysis report

Static analysis result for SHA-256 6c23d4182b77c3a7…

MALICIOUS

PDF

86.9 KB Created: 2021-08-08 11:02:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a2a33dc6a1f3843cfaac66769d291150 SHA-1: 07e6838854ba99716c84c8ee125965b77d328225 SHA-256: 6c23d4182b77c3a720e60fbdcd36d3b608c2de7e568e80479b83d0ea0230299c
156 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to numerous compromised websites, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The embedded URLs are the primary indicators of compromise, leading to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

Heuristics 6

  • 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 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://attep.com/home/sandbox/domains/heekee.com.hk/public_html/ckfinder/userfiles/files/63646904361.pdf
    • https://vdbergelectro.nl/wp-content/plugins/super-forms/uploads/php/files/f4fc339aa3622c878da3509610f77b7e/77652076862.pdf
    • http://szpitalstrzelin.pl/userfiles/files/36602734832.pdf
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160ae1e4f13b0c---pekokavapup.pdf
    • http://hanabi-la.com/uploads/files/29866682236.pdf
    • http://kasargod.net/uploads/file/5562366910.pdf
    • https://lesartsdansmonjardin.com/userfiles/file/20210516215023.pdf
    • https://limpiezasinasel.com/userfiles/files/52247844504.pdf
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad26467157b---65607037374.pdf
    • http://moawin.org/editorfiles/userfiles/files/fajegu.pdf
    • https://tidaksusah.com/contents//files/jijomuxotetodujuv.pdf
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b91a6f18193---57958704886.pdf
    • http://www.centralperdana.com/file/40194039920.pdf
    • https://www.lightingsolutionsinc.net/wp-content/plugins/super-forms/uploads/php/files/39c5154377e46c6a9341686c2347c7ea/zibivivojug.pdf
    • http://bukharajohnscreek.com/sites/default/files/file/waduvujolofixikomagulugow.pdf
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d0cde2279d3---timewopajuxexase.pdf
    • http://htwy.com/upload/file/65924607861.pdf
    • https://vcvscr.cz/www/www/fckphotos/file/9063282542.pdf
    • http://shengnabei.com/uploadfile/file///2021071005530010.pdf
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b12228879e8---192163789.pdf
    • https://www.waterlooarmsnewforest.co.uk/wp-content/plugins/super-forms/uploads/php/files/e6078bf978487e05961008a2abeb9b94/18513815728.pdf
    • https://prosperitas.be/data/assets/file/gujojebok.pdf
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607e01e11d98e---zesixexoxusoluginirolok.pdf
    • http://provia-events.de/pics/fotos/1/file/97260594804.pdf
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/1609dcd46bf23f---12330906094.pdf
    • http://airfa.it/userfiles/file/sefobebudapexojinup.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=queen+size+bed+frame+dimensions+ikea
    • 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_off0000ee30.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE30 16792 bytes
font_01_sfnt_off00010647.bin
81dab3c478f4feb6d1eb1de50e763b933a7fec6e78edbcf310b78ddb4c16e2f7
pdf-font-stream PDF embedded font (sfnt) at offset 0x10647 10820 bytes
font_02_sfnt_off00011f62.bin
2e22e773e7f06621113893e9e76c2a6c56fb72ac7bb6ec1e3ad1858638cbebaa
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F62 17520 bytes