Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5b6970ba1c42379…

MALICIOUS

PDF

81.6 KB Created: 2021-09-10 12:58:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: cc75014cc460ed7b6b62223fe617fc97 SHA-1: bd830222e49f8ef2bb3cb071ab176b8d6a499384 SHA-256: c5b6970ba1c4237956cee9bb126e282b52646955f92e19cd6d36c34541496b8c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised websites or disposable hosting, suggesting a link farm or phishing lure. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this. While no scripts were explicitly extracted, the PDF format can embed JavaScript, which is often used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 https://smidgel.ru/uplcv?utm_term=the+walking+dead+season+9+online+free PDF link annotation
    • https://brothers-music.com/ckfinder/userfiles/files/19922850305.pdfIn PDF document text
    • http://thepokeluau.com/uploads/files/vutivaxenabutupavexaromix.pdfIn PDF document text
    • https://esz.jp/img/editor/files/61394624112.pdfIn PDF document text
    • http://menifee.hanasushichoice.com/uploads/files/gowujenu.pdfIn PDF document text
    • http://chongthamphucthang.com/images/news/files/587177082.pdfIn PDF document text
    • https://inwestorfinanse.pl/userfiles/file/nikoxate.pdfIn PDF document text
    • http://eco-building.cz/UserFiles/File/4101539141.pdfIn PDF document text
    • http://www.letnifestiwal.pl/ckfinder/userfiles/files/tezudasi.pdfIn PDF document text
    • http://ventss.ru/userfiles/files/84112124233.pdfIn PDF document text
    • http://jonkmp.nl/img/cms/file/polesutoselalubevapulufik.pdfIn PDF document text
    • http://roomyab.ir/basefile/roomyabir/files/sagovawesedowixofir.pdfIn PDF document text
    • http://vtvxm.vn/userfiles/file/56011151249.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161377183068c9---82538363772.pdfIn PDF document text
    • http://perilatomsk.ru/ckfinder/userfiles/files/somoraxodojifidonu.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161305d72dfdab---4105023702.pdfIn PDF document text
    • http://e-hematologica.com/users/file/gegikeseful.pdfIn PDF document text
    • http://stauarchitetti.eu/userfiles/files/towakutanin.pdfIn PDF document text
    • http://easyliveconstruction.com/ci/userfiles/files/zanekotevefo.pdfIn PDF document text
    • http://woodbridgeabw.com/uploads/files/sarugaxo.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16134dff38b1a8---7658453321.pdfIn PDF document text
    • http://gpszone.hu/upload/userfiles/file/64041685948.pdfIn PDF document text
    • http://seidels-mineralienwelt.de/images/uploaded/file/nufepujetagakasekamagar.pdfIn PDF document text
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613751367ac48---36590415908.pdfIn PDF document text
    • https://ourcampuswindow.com/ckfinder/userfiles/files/80853145383.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_off0000d918.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD918 18276 bytes
SHA-256: 49ac31e059baf70611a9f7b30a72c3b708ab4d54e52dda516eda08949ad1b27d
font_01_sfnt_off00010835.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10835 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001204c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1204C 10844 bytes
SHA-256: e308f6c38a2b8d0f95c1e64eaef255d69a8306572a5956d56e39bdfc60b6d146