Malicious PDF — malware analysis report

Static analysis result for SHA-256 6cb11db3007531dc…

MALICIOUS

PDF

88.7 KB Created: 2021-06-26 08:49:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: f194a0d07dc09794acbdd62e8ef8fee9 SHA-1: 7f45f3e3037f512e30277e7426d780694afaed72 SHA-256: 6cb11db3007531dc28323d9a1446c646739f760e8ce89c18cc2d96dd456e7b42
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The ML classifier strongly indicated maliciousness, and several heuristics identified the PDF as a link farm pointing to compromised WordPress sites. The document's structure and numerous external links suggest an attempt to redirect users to potentially malicious content or for SEO spamming purposes. No scripts were extracted, but the PDF's nature implies it's part of a phishing or content-luring campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • 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=calisthenics+workout+meaning PDF link annotation
    • https://interesttour.com/wp-content/plugins/super-forms/uploads/php/files/98ec713d44db7eed30ae363d9f550acd/29147134406.pdfIn PDF document text
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160b843febf0b9---betaxirasa.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608018e794cb8---sokezi.pdfIn PDF document text
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160aada341dd29---42545197570.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075aebdb71c6---93472273862.pdfIn PDF document text
    • https://angkoronetour.com/userfiles/file/55877657334.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609844e676292---dodikifesexetuvuvi.pdfIn PDF document text
    • https://ltanimalpark.com/wp-content/plugins/super-forms/uploads/php/files/15a516c8c5fd2b050a4e6016b6026a04/viviguzojow.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/16078ef03c376a---73276708848.pdfIn PDF document text
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/vpdu8mmphgupnavj50os5vmr9c/30106053757.pdfIn PDF document text
    • https://arzhosting.com/calisma2/files/uploads/fimij.pdfIn PDF document text
    • http://aep-tc.com/cache/fck_files/file/volonitisesofux.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/802bdd39f77880787bc6d3753f162778/kolowebibuwulubobowusipa.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c36db1cc311---58917017600.pdfIn PDF document text
    • http://carriewoodfamily.com/clients/5/5b/5b9f2fb360c4065436fb7fe1267c3612/File/nitanogudi.pdfIn PDF document text
    • http://fautographie.org/images/userfiles/files/duzuseluriguwefegilij.pdfIn PDF document text
    • http://basaritarim.net/admin/editor_resim/file/kifujefezujas.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609c0ff3d12e7---zelutomufajowejigutimuw.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/5ac47316396d259545b8818b4eb397c3/lovijufanesuwoge.pdfIn PDF document text
    • http://www.emporiocaritaspisa.it/wordpress/wp-content/plugins/formcraft/file-upload/server/content/files/1607e94dae0ac7---33568968141.pdfIn PDF document text
    • http://unseretochter.com/images/file/xolebaxorizepiruj.pdfIn PDF document text
    • https://eobliecky.sk/userfiles/file/zerinodevaz.pdfIn PDF document text
    • http://www.malagatour.es/ckfinder/userfiles/files/8999214357.pdfIn PDF document text
    • http://lovewhereyoulv.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/ec48acca24fa408d2e78dfd109b28cd9/14192774421.pdfIn PDF document text
    • 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_off0000f6ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6EC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010efe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EFE 16932 bytes
SHA-256: 37e302c025a9134cba8b0d27492407d035e84b4a09229ab7b5a28f1e57a0fc37
font_02_sfnt_off00013a8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A8A 10984 bytes
SHA-256: 8c0656912f2bc5ab8e0a567ace66feee2419ebfd47aacc16c144c5f95c9f2d54