Malicious PDF — malware analysis report

Static analysis result for SHA-256 55a83ac2de027c1b…

MALICIOUS

PDF

84.4 KB Created: 2021-07-30 16:18:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 92095e621a12c7227d60864d06d572b1 SHA-1: 86b678e680ac8e01e7859980406947ea744366db SHA-256: 55a83ac2de027c1b7ceec4c52df053d49ceb57c728894d96080b28e7091a4495
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that function as a link farm, directing users to potentially malicious websites. The presence of compromised CMS upload links and disposable hosting suggests an attempt to obscure the true destination and evade detection. While no scripts were explicitly extracted, the heuristic firings indicate the PDF's primary function is to act as a lure, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://queure.ru/uplcv?utm_term=oxford+junior+english+translation+by+rk+sinha+pdf+free+download PDF link annotation
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a813d4a3fb2---34031431195.pdfIn PDF document text
    • http://sh-ruiyangcpa.com/userfiles/file/2021-6///20216235591344.pdfIn PDF document text
    • https://arvikabc.com/images/uploadedimages/file/92077137082.pdfIn PDF document text
    • https://mahae.hu/files/files/94708505122.pdfIn PDF document text
    • http://thcsnguyenvanhuyen.hoaiduc.edu.vn/ckfinder/userfiles/files/45597180045.pdfIn PDF document text
    • https://www.lightingdynamics.com/wp-content/plugins/super-forms/uploads/php/files/867a30e0d7262f086d84d6ec659ec60b/80379153962.pdfIn PDF document text
    • https://itacademyindia.com/ckfinder/userfiles/files/83020243550.pdfIn PDF document text
    • http://tablica-nieruchomosci.pl/uploades/fckeditorfile/rubakomatudodukudevifo.pdfIn PDF document text
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/d33e73822782609900a782675081adbb/74064760758.pdfIn PDF document text
    • http://akvatoria.by/UserFiles/files/81195713580.pdfIn PDF document text
    • http://jkphotocon.org/data/userfiles/files/25414562470.pdfIn PDF document text
    • http://primaria-ciocirlia.ro/media/file/68835395327.pdfIn PDF document text
    • http://symbioticlifetech.org/attfile/fckimg/file///202106073257_621624850.pdfIn PDF document text
    • http://ytbozhuo.com/upload/file/251321455027.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ef86ae6d73---19442090609.pdfIn PDF document text
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/77840cc111140c76b41fa26944cf5ca2/tukigopumezemupefopixe.pdfIn PDF document text
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a69d6ed44c3---46486340987.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9635b8ffa---79287608586.pdfIn PDF document text
    • http://esthebel.de/userfiles/file/14572623912.pdfIn PDF document text
    • http://mchs67.com/clients/6/60/601da637195afcc8544498be66ee72b0/File/karesumulubemajubak.pdfIn PDF document text
    • http://washchienluoc.com/upload/file/patiforajadipemokifafutiw.pdfIn PDF document text
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/0b58951f15d447036a48b5ea2bc503ea/mulegepunigoxetukedoloz.pdfIn PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/c88c3e83f700c309107f475911e233a2/zukuruwujotakemazexulog.pdfIn PDF document text
    • https://synodradomski.pl/userfiles/file/66463043504.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/ctict2k0cagshu7v8iek6afst5/nekixutumesuraker.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/16079fa4f351b5---77024122038.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_off0000de6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE6D 11568 bytes
SHA-256: 96df9c7e3d9c10e34662ac19c2a2785141e8dfc27ae8fb5ed76394eb413d9409
font_01_sfnt_off0000f96f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF96F 18120 bytes
SHA-256: a5886caa2620f71714896feb4149a0d20a8c4127278a5c6dc9beb2d670914a34
font_02_sfnt_off0001290e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1290E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1