Malicious PDF — malware analysis report

Static analysis result for SHA-256 6a37cd586e0ab7d2…

MALICIOUS

PDF

76.1 KB Created: 2021-09-05 17:17:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2eb97051f2369cd0b9f857baafc583c6 SHA-1: ad6c0912ea35652c4a1c6bf9500149620160f272 SHA-256: 6a37cd586e0ab7d20edd4264bba90e09e409dfaece8a05eb9687f07cd5eef494
204 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript, which is a common technique for executing malicious code within PDFs. It also features a large number of external links, many pointing to compromised CMS upload directories or disposable hosting, suggesting an attempt to obscure the final destination. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 8

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://sun-green.eu/ckfinder/userfiles/files/93966186848.pdf
    • https://i-chat.tw/js/ckfinder/userfiles/files/70367480817.pdf
    • http://benevolo.it/userfiles/files/20462346100.pdf
    • http://myrbacken.se/login/ckfinder/userfiles/files/befunipegekow.pdf
    • http://suriyedostlukdernegi.org/image/files/8107701755.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/e32asco84e5047irp8ivhjoma7/letoribule.pdf
    • http://avanti-kuhni.ru/upload/files/21600725980.pdf
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/160fc31fbda392---80845721952.pdf
    • http://ahdjcm.com/upload/files/muwerizewasuzokemadab.pdf
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/160b40422b73ec---69549978210.pdf
    • https://mahae.hu/files/files/16010911096.pdf
    • https://santechnikosdarbai.lt/images/files/45052933667.pdf
    • http://alpha-cp.com/userfiles/file/wofipojeluwesetokev.pdf
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/16073706aef305---zuxofa.pdf
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dad3fba1ae2---bulepa.pdf
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606fe99824a6c---dujavozurivuro.pdf
    • https://panificiopasticceriabattaglia.it/file/xinuzefuz.pdf
    • http://sl-light.ru/design/img/upload/file/tegefabugupo.pdf
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e8bc3f9f9e9---borawuw.pdf
    • http://an-ocn.ru/ckfinder/userfiles/files/porabojetixifutawusuxorek.pdf
    • http://a1-automotivegroup.com/upload/files/18343148426.pdf
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/f3e69199b02e4380f1c47a33abf82dc6/57942304830.pdf
    • https://cgeminfos.ma/upload/file/nudakezenekaratefideto.pdf
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16080eb5a13491---lujusuzebidikujo.pdf
    • http://aarogyamedico.com/userfiles/file/kefoximupulagesiwiw.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=advanced+robust+and+nonparametric+methods+in+efficiency+analysis+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bf2b.bin
6aec2eafde515068bbf095d6bf447745818b55932e9124463e52de6e776e7e51
pdf-font-stream PDF embedded font (sfnt) at offset 0xBF2B 19180 bytes
font_01_sfnt_off0000efe2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFE2 16792 bytes
font_02_sfnt_off000107f9.bin
0a0e061c30712a8a886bb509374167c67acc6ba97804055ea8b52184c112eae2
pdf-font-stream PDF embedded font (sfnt) at offset 0x107F9 11288 bytes