Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf4d1ed87cd81e11…

MALICIOUS

PDF

85.6 KB Created: 2021-09-13 16:34:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 90fe4994899c6e72a64eab5f9019255b SHA-1: 4730d9ab5af444fdb030c3b9902dc6d4fce6d2d3 SHA-256: cf4d1ed87cd81e11b0e8a6ed1725f9bad28c466a3422911ef715b125f332893f
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to various domains, many of which are flagged as unknown or potentially compromised. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of external URIs and link farms suggests an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://smenergy.kr/uploaded/file/168039091461334ac25d95e.pdf
    • https://cailux.lu/userfiles/files/lugizuv.pdf
    • https://www.ijestr.com/ckfinder/userfiles/files/xavorotuwetar.pdf
    • https://bwawarszawa.pl/upload/file/gigodod.pdf
    • http://gruppocinofilomarsalese.com/userfiles/files/8566739403.pdf
    • http://patrick-jardinage.fr/ckfinder/userfiles/files/valoramigutukalami.pdf
    • http://dejede.com/userfiles/file/60055151236.pdf
    • https://kaptenhoki.net/contents/files/62017122532.pdf
    • http://creaorganization.com/depo/sayfaresim/file/48866697306.pdf
    • http://jd6618.com/jd6618/file/2021-9/file/LwpCms2021_09_08_10_24_47_8118.pdf
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/s9vb0svp2jp8mna4jhcrajlb9m/87968010121.pdf
    • http://youngshiny.com/userfiles/file/1631318197.pdf
    • http://tdsns.ru/userfiles/file/muwewebodeko.pdf
    • http://chanhbon.vn/media/ftp/file/naxonuvezamomunabir.pdf
    • http://boonfagrandhome.com/user_img/files/45558985020.pdf
    • http://hzzxtl.com/UploadFile/file/20210913080411782.pdf
    • http://mellorymotors.ru/admin/ckfinder/userfiles/files/mafukote.pdf
    • http://ville-dammarie.com/ckfinder/userfiles/files/65258912112.pdf
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613366cbe1f1b---zotanafumajojalizajitalil.pdf
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131b6e6c172d---vavokofez.pdf
    • http://odnoklassniki-files.ru/images/uploads/files/bival.pdf
    • http://kargo-box.com/uploads/files/43987213207.pdf
    • https://advance-pack.com/editor_upload/file/repufedoga.pdf
    • http://sntaviator.ru/ckfinder/userfiles/files/389202317.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=best+mods+for+minecraft+pe
    • 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_off0000e927.bin
255b550ab2b35f0022b397b623cce3a9940fbb43b80917a1927e5351d603639f
pdf-font-stream PDF embedded font (sfnt) at offset 0xE927 18056 bytes
font_01_sfnt_off00011800.bin
62695881b47ac461f4c3875ecb6fbe6a1ed2fd1b37aab04f8999e019bd164e15
pdf-font-stream PDF embedded font (sfnt) at offset 0x11800 10788 bytes
font_02_sfnt_off000130da.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x130DA 16792 bytes