Malicious PDF — malware analysis report

Static analysis result for SHA-256 918a8692c42da863…

MALICIOUS

PDF

77.5 KB Created: 2021-09-17 19:45:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ada74e602f58fc721cc248762e620bea SHA-1: 18de553812139293c2695fbcc1148c495953a323 SHA-256: 918a8692c42da8630203c93b67750a5e9e13ef8e68520ffb1621e58917f061a4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which are part of a link farm hosted on disposable or compromised domains, suggesting a phishing or redirection attempt. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to malicious sites or exploit vulnerabilities. The file's structure and heuristic firings point towards it being a malicious PDF designed for initial compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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://ntvietnga.com/upload/files/14338829911.pdf In PDF document text
    • http://legalinet.eu/userfiles/files/33386972885.pdfIn PDF document text
    • http://www.mostenpo.jp/userfiles/files/8681608798.pdfIn PDF document text
    • http://primebrokeragetx.com/ckfinder/userfiles/files/mefex.pdfIn PDF document text
    • http://fazendasaojudastadeu.net/fotosempresa/files/56671940369.pdfIn PDF document text
    • https://highendteen.com/userfiles/files/15989589522.pdfIn PDF document text
    • https://partnermind.cz/images/files/2143483155.pdfIn PDF document text
    • http://matras-devison.com/upload/file/pasebizizidi.pdfIn PDF document text
    • http://avandcie-energy.com/ckfinder/userfiles/files/zoparofekazepogi.pdfIn PDF document text
    • https://eletmodguru.hu/files/files/tosutunovikodorujisol.pdfIn PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/a8f643d842466ce047b2ab8d80713196/33558762883.pdfIn PDF document text
    • http://sys-svinding.dk/userfiles/file/xakavaj.pdfIn PDF document text
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16141b7872d221---86253656114.pdfIn PDF document text
    • http://anshan56.cn/userfiles/file/16318676641345697480.pdfIn PDF document text
    • http://jtg-antracyt.pl/files/file/54314230749.pdfIn PDF document text
    • https://themodernla.com/wp-content/plugins/super-forms/uploads/php/files/bc3d6fdb2374494d4262a7c125809033/vomunagenilikufavaji.pdfIn PDF document text
    • http://teedinmaesai.com/user_img/file/renavolivoxavefaxigiluz.pdfIn PDF document text
    • http://www.detskaoptika.cz/ckfinder/userfiles/files/11603733623.pdfIn PDF document text
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/c625e3b03398ccfc061189767ed9a9c5/31418716367.pdfIn PDF document text
    • https://motelandratecuci.ro/userfiles/file/24989607247.pdfIn PDF document text
    • http://obasekiestates.com/UserFiles/file/68290226339.pdfIn PDF document text
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/7ms4jef1icsangt6lcbs0olfmk/8017821854.pdfIn PDF document text
    • https://ysh.my/userfiles/file/niwitafu.pdfIn PDF document text
    • https://ferest.ro/imagini_ws/27808992656.pdfIn PDF document text
    • http://stagegator.scorchmark.com/stagegator/ckfinder/userfiles/files/69000210579.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=download+andu+mod+apkPDF 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_off0000c2ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2FF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000db16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB16 10240 bytes
SHA-256: d97ade09771f90729452da62650b34e0f490fc203a14ba002566a049f972b09f
font_02_sfnt_off0000f211.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF211 21248 bytes
SHA-256: 89e6209fa906e3bf24d1e5503de0efecc99e9225c7febffbbd824836a5d1ac53