Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b3c85b54fb809d2…

MALICIOUS

PDF

81.2 KB Created: 2021-09-15 20:03:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: ad626989046361107519cda9506557fd SHA-1: a9e0ddff3e4005e50059e6d0f6242959428e19c4 SHA-256: 7b3c85b54fb809d2f3b6cfa3ae8f66a9c51e0ad5aa1a8c87703a9aa2c0bd1656
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with numerous URLs pointing to potentially compromised or disposable hosting sites. The presence of external URIs and link farm characteristics suggests the document's primary purpose is to redirect users to external malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://sendedianqi.com/upload_fck/file/2021-9-2/20210902050351670353.pdf In PDF document text
    • http://ageofwonders.buka.ru/sadm_files/xenetido.pdfIn PDF document text
    • http://biznesfishki.ru/files/userfiles/files/nofiregefarexobup.pdfIn PDF document text
    • http://eviljoy.com/UserFiles/File/virulizavizisinopukexudu.pdfIn PDF document text
    • http://industrialsupplies.pk/userfiles/files/wivekutipufa.pdfIn PDF document text
    • http://telegid.tv/userfiles/file/76400345685.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/d3a0b6c75077257e9ace059a37fd8d4e/11095290885.pdfIn PDF document text
    • http://americasbestwingsbeltsville.com/uploads/files/sakeko.pdfIn PDF document text
    • https://lifo-sea.com/ckfinder/userfiles/files/80482555032.pdfIn PDF document text
    • https://washlounge.in/ckfinder/userfiles/files/kukosijagamidusepolinuma.pdfIn PDF document text
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141767c9d107---43963553454.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/8d0b4f634837b6c24ac37a891d52bd55/55923439565.pdfIn PDF document text
    • https://gencshow.com/upload/ckfinder/files/9579182146.pdfIn PDF document text
    • https://nguyenhungstone.com/uploads/image/files/nadosuwekakaja.pdfIn PDF document text
    • http://psychologkmalinowska.pl/ckfinder/userfiles/files/refozapalowajed.pdfIn PDF document text
    • https://camelcarpet.org/d/files/60192231302.pdfIn PDF document text
    • https://xn--72ca1bzcdf9cg5df4n5a8cei.com/userfiles/files/vazezako.pdfIn PDF document text
    • https://hahapediatric.com/uploads/files/202109150605247926.pdfIn PDF document text
    • http://besttailor.info/ckfinder/userfiles/files/36562368542.pdfIn PDF document text
    • http://coreaad.com/DreamDataUpload/file/bimod.pdfIn PDF document text
    • http://kayamedbursa.com/userfiles/file/21349849374.pdfIn PDF document text
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613827122a933---lafeji.pdfIn PDF document text
    • https://hram-uspeniya.ru/ckfinder/userfiles/files/45034756720.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131d403dbe67---30099472591.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=among+us+crack+iosPDF link annotation
    • 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_off0000db61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB61 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f373.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF373 17032 bytes
SHA-256: 017632e8a291c35b81a6b385d3a493fedc463c303da6b2f60f7e781620162d48
font_02_sfnt_off00011f9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F9C 10472 bytes
SHA-256: 48c76a793374007418a0577dce650ace222faac6ce7475bc6b82b08535dd200e