Malicious PDF — malware analysis report

Static analysis result for SHA-256 f37df4d5e290c25c…

MALICIOUS

PDF

86.8 KB Created: 2021-09-05 04:34:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: d571f9e79e391f672e2155b3bfb522d8 SHA-1: c4439cf0a7147715b09825520b1af45ef43470b4 SHA-256: f37df4d5e290c25c80679d34527dc01cb0a1d0d70dfe42f84cbcf2d6900af545
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to numerous domains, many of which appear to be compromised WordPress sites or disposable hosting. The ML classifier strongly indicates maliciousness, and the presence of embedded URLs suggests an attempt to redirect users to malicious content, likely for phishing or malware distribution. No scripts were extracted, but the overall structure and URL patterns are indicative of a malicious lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://crysiq.ru/uplcv?utm_term=comptia+linux%2B+study+guide+exam+xk0-004+4th+edition+pdf PDF link annotation
    • http://robbes.nl/media/files/33037613449.pdfIn PDF document text
    • http://klefmarken.se/upload/file/34065757699.pdfIn PDF document text
    • https://www.idromeccanicasrl.com/idromeccanicasrl.com/wp-content/plugins/super-forms/uploads/php/files/484ea4d6a5c8549504a3d3db17437e69/tubasipinobolufejipakatun.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/16096b274c79b7---figitivagu.pdfIn PDF document text
    • https://valserve.in/web/k/main_admin/ckfinder/userfiles/files/41415962279.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/160735802eed56---jijapuseleveretujimetidax.pdfIn PDF document text
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/c81d81521e9c539d0ff5f84586a82a97/80912144343.pdfIn PDF document text
    • https://tranduongauto.com/app/webroot/files/images/pages/files/59756235896.pdfIn PDF document text
    • https://info-jimukyoku.jp/lot/upload/files/71732495907.pdfIn PDF document text
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/fd5ecefbbb24d2c780d656edf374a810/26705309881.pdfIn PDF document text
    • https://sts-cct.com/app/webroot/userfiles/files/44106213808.pdfIn PDF document text
    • http://www.jobsincrete.gr/images/_user_na/file/sabavizuwegelerilonisa.pdfIn PDF document text
    • http://maasmartcity.com/userfiles/file/gixerofidugisalonagajo.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fec9125c8b---zovavuveretezozimisub.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c73e4649ee4---vazagidorumuxalozu.pdfIn PDF document text
    • http://fairmonteast1975.com/clients/0/01/014dde3c838f86fef2ac1d31a86c415b/File/32843824306.pdfIn PDF document text
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files//jipuros.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606cee68216fb---lirepikisawuvoris.pdfIn PDF document text
    • http://klaaswester.nl/img/file/34698620421.pdfIn PDF document text
    • http://pericosrentcar.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160836f77bf016---wasopiresafexanunepina.pdfIn PDF document text
    • http://rracc.com/file_media/file_image/file/59245923307.pdfIn PDF document text
    • http://www.playerclub.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8151b81a3---84748345849.pdfIn PDF document text
    • http://studioaba.net/userfiles/files/82027805350.pdfIn PDF document text
    • https://aimara-bg.com/userfiles/file/75396544285.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_off0000e8f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8F6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010108.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10108 18796 bytes
SHA-256: f62c2d97da92f970f1f83889463fa53a84d68175dd6cc057eefd60265f542c9a
font_02_sfnt_off00013204.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13204 11520 bytes
SHA-256: 45a46a46d57a47ec0d036d6d0794736e8097fb8ae5dfa8dd2ba72f0c1d184be1