Malicious PDF — malware analysis report

Static analysis result for SHA-256 6e33857418610506…

MALICIOUS

PDF

88.5 KB Created: 2021-07-01 14:01:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 7edc92111c4234b46577ba0ee0e7bf8e SHA-1: 8a37239560b86e8ce6a47410419044e9e1889a31 SHA-256: 6e338574186105066fcbb5cebd3e4e6127d5a92bf10953895ac51f3cdce223a2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites, suggesting a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were explicitly extracted, the nature of the embedded links and the heuristic firings point towards a malicious link farm designed to lure users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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 https://wastran.ru/uplcv?utm_term=how+to+solve+using+cramer%27s+rule PDF link annotation
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/4vlont247uv23pejo9ub1m6cpq/nezawok.pdfIn PDF document text
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606edaeb68a8c---13805777434.pdfIn PDF document text
    • https://asset-books.com/userfiles/file/tofogejof.pdfIn PDF document text
    • http://simmsfamilyreunion.com/clients/9/98/98d47f1658d09d39d77ba56043454c9c/File/ligugoxesizigebesije.pdfIn PDF document text
    • http://eltonltd.ru/sites/default/files/uploads/rivifejolaxozev.pdfIn PDF document text
    • http://turagent007.ru/userfiles/file/57220901241.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160809d2bb46b8---zonopebunidetulawewini.pdfIn PDF document text
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/789765cab7120a1139de1d299f4620f9/58081499720.pdfIn PDF document text
    • https://samowar.ch/upload/file/setopefof.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/gmhajkkqh2km8e0kvp7va1dhl7/jovisefukutozopubupuzemu.pdfIn PDF document text
    • http://timelessmebel.ru/wp-content/plugins/super-forms/uploads/php/files/a3126073f97240b2d0a93c67e95f3524/15862293860.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/49ca19cc8171fa541c43a61440d91518/rakinimema.pdfIn PDF document text
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/160794f902e0df---xafirupasojizigojimeli.pdfIn PDF document text
    • https://www.kunapak.com/wp-content/plugins/super-forms/uploads/php/files/j0lmkpd67u6uv65lucdodo2lrn/wegefuxidejutuvodov.pdfIn PDF document text
    • http://i-daa-wl.de/userfiles/79936025060.pdfIn PDF document text
    • https://envomask.com/wp-content/plugins/super-forms/uploads/php/files/f95c314f7b3ec9e4fd57729cb19c96a6/mogexitiderimud.pdfIn PDF document text
    • http://sns.hu/_user/file/loxakarigotusadufawumu.pdfIn PDF document text
    • http://krzysztofmalec.pl/gfx/fck/file/11256832577.pdfIn PDF document text
    • http://klpa.net/userData/board/file/geranakiniruwireriboruva.pdfIn PDF document text
    • http://xn--h49avwqct32ewe967crscpsaz7d.com/ckupload/files/kosivabukinukiserotefu.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607effe4adb1c---33564634807.pdfIn PDF document text
    • http://fbchitchcock.org/clients/8/8b/8bdff38a390027835eb24981312b950c/File/67995904313.pdfIn PDF document text
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files//segolugoti.pdfIn PDF document text
    • http://angeladaniel.eu/uploads/files/mikilozenexapif.pdfIn PDF document text
    • http://drivingschool-brno.eu/files/45962382781.pdfIn PDF document text
    • http://duoctruongxuan.vn/userfiles/image/file/33951080679.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_off0000f37d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF37D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010b8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B8F 17992 bytes
SHA-256: 3a2cb535e4f65215defea3e5c008f015c6a33b2bf5eb12fb98e7715bf1fcde12
font_02_sfnt_off00013a9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A9F 10848 bytes
SHA-256: df5aaf073a71e4e018120ab07741dd984779643d3b16a4b5ba2751254f39fe7b