Malicious PDF — malware analysis report

Static analysis result for SHA-256 d5a90bd36e3f2c19…

MALICIOUS

PDF

85.8 KB Created: 2021-09-09 07:37:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: bb9bb2150d8d9c9afcb549848d64704b SHA-1: 8164584df170cc5827344b6c17d9b7a8f09e8650 SHA-256: d5a90bd36e3f2c19b4b05de57d473a2822a93817bc138d52a271c2b6e4b31f2f
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to disposable hosting or compromised CMS upload storage, indicative of a link farm used for distributing malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are common for initial-stage infection vectors.

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 http://hkalc.com/userfiles/81251246655.pdf In PDF document text
    • http://malifer.hu/upload/file/pitubikokixupedu.pdfIn PDF document text
    • http://vlaamspatientenplatform.be/_plugin/ckfinder/userfiles/files/lujuvux.pdfIn PDF document text
    • http://windowsplusllc.com/ckfinder/userfiles/files/61394618405.pdfIn PDF document text
    • http://sanphamhanquocymy.com/uploads/files/juvixipirur.pdfIn PDF document text
    • http://jiendurancecoaching.com/ckfinder/userfiles/files/pipenemexugajifutivabuve.pdfIn PDF document text
    • http://bilateralmatters.org/userfiles/file/12492003501.pdfIn PDF document text
    • https://s-h.cc/uploads/files/202109020915517364.pdfIn PDF document text
    • http://internet-trade.eu/UserFiles/file/53785754798.pdfIn PDF document text
    • http://debsecond.net/UserFiles/File/78366211040.pdfIn PDF document text
    • http://gartenmessebau.de/uploads/files/dixeladojoxur.pdfIn PDF document text
    • http://fpempresa.cen.es/userfiles/files/luxugibimewasesob.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16131ca87a36b4---55019804193.pdfIn PDF document text
    • https://paeonia.ch/userfiles/files/toviju.pdfIn PDF document text
    • http://drukarnia-skawina.pl/app/webroot/media/files/33745690540.pdfIn PDF document text
    • https://www.tristar-technology.com/ckfinder/userfiles/files/38329556742.pdfIn PDF document text
    • http://evolution-dev.com/file_media/file_image/file/dawujusuxosu.pdfIn PDF document text
    • http://shoreluxurylimos.com/userfiles/files/28886991866.pdfIn PDF document text
    • http://hart-metale.pl/gimnazjum/userfiles/file/jeleronamexaberitosogexux.pdfIn PDF document text
    • https://artbynela.com/uploads/file/vigesix.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/161341a9420da0---99077483957.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131059c2b4d8---53002399856.pdfIn PDF document text
    • http://autoscuolauniversale.it/userfiles/files/96657481533.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=demon+slayer+mugen+train+full+movie+free+onlinePDF 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_off0000e753.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE753 10840 bytes
SHA-256: 981bf609d94980af8832ca3d70aacf0813a5abdc1313220e1efd1bf0c3ef357d
font_01_sfnt_off00010066.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10066 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011878.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11878 18548 bytes
SHA-256: c5115a768eb68087e27c2765a423bc28782d608c15c292b9804af5794abacc7f