Malicious PDF — malware analysis report

Static analysis result for SHA-256 83e07e14f40320e2…

MALICIOUS

PDF

75.0 KB Created: 2021-09-24 23:13:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: eef784a7d0d50eeb9eea3473858fe098 SHA-1: 8c800662d09bef1e854ef8d112ba5d07d041e32f SHA-256: 83e07e14f40320e29425ba504c4e6a9f13cd2effd8def4ed730075d9543c2c2c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Numerous heuristics point to the PDF acting as a link farm, redirecting users to various compromised websites and potentially disposable hosting. The presence of external URIs and embedded URLs suggests the primary function is to lure users to external malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://crysiq.ru/uplcv?utm_term=isl+light+remote+desktop+apk PDF link annotation
    • https://anhhuynoithat.com/asset/files/doxizodosumidalikufepi.pdfIn PDF document text
    • http://fszhenjia.com/upfolder/e/files/20210909054731.pdfIn PDF document text
    • http://old.smartplus.pl/ckfinder/userfiles/files/43484859844.pdfIn PDF document text
    • https://barcelona-health.com/files/galeria/files/63582985518.pdfIn PDF document text
    • http://thelonerangerfanclub.com/ckfinder/userfiles/files/xesamixibijevup.pdfIn PDF document text
    • http://ornito-silesia.eu/userfiles/file/62862944873.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/5e7a402bb9f1bfd760b3799a7fa37232/68449982632.pdfIn PDF document text
    • http://aimecostruzioni.it/userfiles/files/rodumo.pdfIn PDF document text
    • http://fzsvybbs.at/userfiles/file/67619087675.pdfIn PDF document text
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132f4c95464c---regaki.pdfIn PDF document text
    • https://computerzone.pk/file/vijanafalezuxupujifokub.pdfIn PDF document text
    • http://cesurmakina.com/userfiles/file/jatojolofibuf.pdfIn PDF document text
    • https://kaparatt.com/images/File/20233389572.pdfIn PDF document text
    • http://yonseri.org/userfiles/files/37706601146.pdfIn PDF document text
    • http://kxnjl.com/userfiles/files/sorazavi.pdfIn PDF document text
    • https://unchiulmihai.ro/files/fckeditor/file/webujoleluvev.pdfIn PDF document text
    • http://gfk-schwimmbad.de/i/File/58066291042.pdfIn PDF document text
    • http://cbelmira.com/wp-content/plugins/super-forms/uploads/php/files/f222334e89381fef426af67841e72820/bagubodarejar.pdfIn PDF document text
    • http://es-manzokudou.com/yamituki-n/uploads/files/kirizujaze.pdfIn PDF document text
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/3e59827983ab4283ac6da61af50d65d0/pikuzuf.pdfIn PDF document text
    • https://srsatta.com/ckfinder/userfiles/files/buzezevikel.pdfIn PDF document text
    • http://alliance-ic.ru/uploads/file/30250596931.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab8e88f652---vozosumota.pdfIn PDF document text
    • https://mintowncoffee.net/uploads/images/files/84205380492.pdfIn PDF document text
    • http://toptoptraining.ru/img/upload/file/sixulipumezipototaf.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_off0000baca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBACA 10776 bytes
SHA-256: cc40c6d771512e248f8ce8e99ea19ca27c363b7f78f394e206135b9abe927438
font_01_sfnt_off0000d35b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD35B 18704 bytes
SHA-256: cb7def7379f83287aa6085cc72d01c90a90ccc054dff2f0e5ba54a319466af7c
font_02_sfnt_off0001043d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1043D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1