Malicious PDF — malware analysis report

Static analysis result for SHA-256 664c3a4913dea647…

MALICIOUS

PDF

77.9 KB Created: 2021-10-07 15:55:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: d279978c43b63a860d7fd49d5d68be10 SHA-1: f3fd4879eceef1cb9f356676686c2f0633094ce8 SHA-256: 664c3a4913dea6470a517c17a30ec9b96da91280d7967683d3b8ebe65e3c3732
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by a machine learning classifier and ClamAV, flagging it as a phishing trojan. It functions as a link farm, containing numerous URLs pointing to compromised WordPress uploads and disposable hosting sites, designed to redirect users to further malicious content. The presence of multiple external URIs and link farm heuristics strongly suggests a phishing or redirection attack.

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://www.firengo.com/userfiles/files/50058507976.pdf In PDF document text
    • https://coebmsf.com/userfiles/file/tegonu.pdfIn PDF document text
    • http://baracenter.be/userfiles/file/7675678731.pdfIn PDF document text
    • http://inistor.com/ufiles/files/relekixugimu.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/aab8ffae746fdd77cc73261d60169c70/51601418345.pdfIn PDF document text
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/fg37sd5oln42nvn8m6r8jc102o/17882931438.pdfIn PDF document text
    • https://cyberbirddog.com/userfiles/files/91338107987.pdfIn PDF document text
    • http://www.peritaonline.es/ckfinder/userfiles/files/25282871788.pdfIn PDF document text
    • http://ourgans.org/userfiles/files/kebusasizetugabasifakexa.pdfIn PDF document text
    • https://www.pollackmihalyiskola.hu/ckfinder/userfiles/files/josotibo.pdfIn PDF document text
    • http://vtdsbinhthuan.vn/public/uploads/userfiles/file/togobuxakebit.pdfIn PDF document text
    • http://tpfish.com.taipei/archive/upload/files/51406138765.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202110020614066298.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/161500ea0be871---50043828106.pdfIn PDF document text
    • http://kiemdinhcan.com/Images_upload/files/67535088999.pdfIn PDF document text
    • http://kzlo.pl/fotki/fotki/file/sojonusakemulanub.pdfIn PDF document text
    • http://safiorida.dk/operatori/userfiles/file/jogapinete.pdfIn PDF document text
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/b115f4732e94c8725e30dc1805d4caf5/51545218522.pdfIn PDF document text
    • http://t-p-fortune.com/userfiles/file/77729307840.pdfIn PDF document text
    • http://slabowidzacy.smprzemysl.pl/ckfinder/userfiles/files/luduxirenimiduwikoxiziwix.pdfIn PDF document text
    • https://ncsccalgary.com/userfiles/files/nedadekoxigaxu.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/1615cabafe0f0a---55542459723.pdfIn PDF document text
    • http://accronline.com/userfiles/file/vuwufal.pdfIn PDF document text
    • http://studiophotosfashion.it/userfiles/files/71718567026.pdfIn PDF document text
    • http://xn--80aaa6aachkjln0qra.xn--p1ai/ckfinder/userfiles/files/35678143910.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=effect+of+common+ion+on+solubilityPDF 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_off0000c7f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7F5 10572 bytes
SHA-256: fbf3f091c6b417b02dd4a29f21388730d535273bc4b5e5c0faad653b438dea6b
font_01_sfnt_off0000e01e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE01E 19148 bytes
SHA-256: ad076aa94dd2f78188b73b4d693d56d074c2b7fba59e4d5334b25c1baab96bdd
font_02_sfnt_off000111e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111E7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1