Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4f42cda7d71d63e…

MALICIOUS

PDF

75.1 KB Created: 2021-09-03 07:01:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 18d33d9e259bd225fc6f4ece9ae30c0c SHA-1: 4ee6155044f3cd92db1e6b1c95eb081d91805ba5 SHA-256: c4f42cda7d71d63e62af4b309ad7ec9dfe0b4693cf1ae37b2663cdf0d9bec049
156 Risk Score

Malware Insights

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

The file was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to external PDF files hosted on compromised websites, suggesting a phishing or malware distribution scheme. The presence of multiple external URIs and link farm heuristics supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/gg897jh6t7vcjram40o6qn01dg/radida.pdf In PDF document text
    • http://kyanite.tv/userfiles/file/lutajomonovufamoke.pdfIn PDF document text
    • http://itkaufmann.com/images/fckimages/file/wumoxonusa.pdfIn PDF document text
    • https://ezgoe.com/10005001208290177/ckfinder/userfiles/files/xibotexuvexogavuxotedidi.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608905de4405b---wigipo.pdfIn PDF document text
    • https://prokoncept.hu/admin/blogfck/image/file/47945647202.pdfIn PDF document text
    • http://zamokugrofa.sk/admin/fckeditor/file/69406530110.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/8ba3018acf07cae766059f82bab598aa/68036688327.pdfIn PDF document text
    • https://bloomland.com/sites/bloomland.com/files/27430067489.pdfIn PDF document text
    • https://www.acetechnology.co.in/wp-content/plugins/super-forms/uploads/php/files/0rhglggjjjifnirq12hqur83d4/xovugefitijivekufelekuf.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1607326e86b9e1---tolinipixulutin.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b5783d48479---96751094690.pdfIn PDF document text
    • http://meadescafe.com/userfiles/file/53162519651.pdfIn PDF document text
    • http://waetsukai.jp/system/ckfinder/userfiles/files/33014668120.pdfIn PDF document text
    • http://xn--12cbg9dihj7egda2g6a7dceb1d2cp4nvgf4f.com/datas/files/kexixabukodefaxoxuzufug.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087d578bfae8---bavigetibigupusuxeb.pdfIn PDF document text
    • https://ap-qatar.com/userfiles/files/mokab.pdfIn PDF document text
    • http://denis-lefebvre-services.com/fichiers/file/95515709511.pdfIn PDF document text
    • http://dayuntang.com/assets/uploads/ckedit/files/20210902053854.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a659a6b3959---kexirosunisisuvogiz.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/9848601cc1d325bef7fc673ebadfbca1/bomameb.pdfIn PDF document text
    • https://joinvita.com/neu/userfiles/file/9119347829.pdfIn PDF document text
    • http://myucmas.com/userfiles/file/tilaboxemolo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=the+synthesis+and+characterization+of+inorganic+compounds+jolly+pdfPDF 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_off0000c0b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0B9 16496 bytes
SHA-256: a9784bba956e11b0e8bd6c1657e599a162395723f071ac701d348dd7355de8d8
font_01_sfnt_off0000eae2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAE2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000102f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102F9 11432 bytes
SHA-256: 7b99344e905af1fc4b94adde0923162843ef4329c12de7817e868c097f1d9199