Malicious PDF — malware analysis report

Static analysis result for SHA-256 d661505f68dbd3a1…

MALICIOUS

PDF

92.7 KB Created: 2021-08-17 08:49:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: a08d6cc1af50dc8db34c361048675b91 SHA-1: a8e389557b92aed4288b681d008c17612f80f4ea SHA-256: d661505f68dbd3a1a9b6f37c28aa4028430437f68c4834006410c542b28b3fad
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous external links, including a link farm on disposable hosting and links pointing to compromised CMS uploads, suggesting it's used to redirect users to malicious sites. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this. No scripts were extracted, but the overall structure and heuristics point to a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9876

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 https://garglob.ru/uplcv?utm_term=synonym+context+clues+worksheet+pdf PDF link annotation
    • https://travelinnsuites.com/nbloom/fckuploads/file/91417272749.pdfIn PDF document text
    • https://toppelletmachine.com/d/files/zovedakilibavosake.pdfIn PDF document text
    • http://zaintik.org/files/galeria/files/dokanutofu.pdfIn PDF document text
    • https://tw-itemaos.com/ckfinder/userfiles/files/juwiran.pdfIn PDF document text
    • http://coiffurenais.com/userfiles/file/wubowiteneberutif.pdfIn PDF document text
    • http://evohome.pl/userfiles/file/23724442317.pdfIn PDF document text
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/160b3c2e2407f7---39267857661.pdfIn PDF document text
    • https://mldom.xyz/web/img/podborky/files/pofejarulowunetogamale.pdfIn PDF document text
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611adf51d9923---78088145146.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/16075ace581fda---nojaxogigevamemid.pdfIn PDF document text
    • http://dfwsedan.com/nbloom/fckuploads/file/61280198040.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6d4c17347f---64990614106.pdfIn PDF document text
    • http://fongyoskert.hu/userfiles/files/livumagusolew.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/1606d13e90384b---loburojedezowesek.pdfIn PDF document text
    • https://xn----9sbccjdbca7cyaieg1a3j.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/816c414ac7b0de8458da0e76ad149493/22671098294.pdfIn PDF document text
    • https://dmshospital.com/mm_engg/files/41501088544.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/xezikaxuwot.pdfIn PDF document text
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/40738829478.pdfIn PDF document text
    • https://oncallanatomist.org/ckfinder/userfiles/files/23864841365.pdfIn PDF document text
    • http://hfengly.dk/skoleportalen/userfiles/file/fupugatub.pdfIn PDF document text
    • https://taechoclub.com/FileData/ckfinder/files/20210730_950A63D312E2FF02.pdfIn PDF document text
    • https://www.spreefahrten-berlin.de/wp-content/plugins/super-forms/uploads/php/files/r804vc63oah444ejj1irt6e3qn/kitukovebekavitatawoz.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6c19d66316---lodidewuvatex.pdfIn PDF document text
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609433cb5806a---fodatafubo.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af8d6b59d31---71400593519.pdfIn PDF document text
    • https://fellowpeo.com/wp-content/plugins/super-forms/uploads/php/files/0e86c060e53c24f5a3c236639a030917/daralefifewatokar.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_off00010472.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10472 11200 bytes
SHA-256: ef90c206613b97ee54ca535cbe445f1fc67337d50270186c25a4fa6efbe7974e
font_01_sfnt_off00011e90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E90 17340 bytes
SHA-256: eb732288befdb704a523c6b44cc7489a4240f64f38a10ec38b4f73d8ae64170d
font_02_sfnt_off00014bbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14BBB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1