Malicious PDF — malware analysis report

Static analysis result for SHA-256 a123b66ce1fd07d6…

MALICIOUS

PDF

78.0 KB Created: 2021-07-02 22:01:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: ba1da13ce2af252a697cbcbcd869f70d SHA-1: 18b121f616847f7a5d6f87012abc57e7bdd57e8f SHA-256: a123b66ce1fd07d6e94b9efc41670bd1f2e6c8b5b9602cf6ba1d2fb97935f691
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains numerous external URLs, many pointing to compromised WordPress sites, suggesting a link farm or phishing lure. The PDF's structure and the presence of embedded URLs indicate it's likely used as a delivery mechanism for malicious content, possibly via spearphishing.

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 https://philabc.ru/uplcv?utm_term=little+fires+everywhere+quotes+with+page+numbers PDF link annotation
    • https://lasvegasrebath.com/wp-content/plugins/super-forms/uploads/php/files/d6600df1a089b178f0f8fa91baabc57c/povedawonovov.pdfIn PDF document text
    • https://telewebmarketing.com/FCKeditor/file/45585204521.pdfIn PDF document text
    • http://mamaskitchenorder.com/uploads/files/65392235605.pdfIn PDF document text
    • https://bringem.de/wp-content/plugins/super-forms/uploads/php/files/04bc5578ca394f713a1ff215845d4d97/11189217051.pdfIn PDF document text
    • http://obasekiestates.com/UserFiles/file/lozev.pdfIn PDF document text
    • https://ltssinternational.com/res/wysiwyg/file/ralat.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ef38f08558---dusurulevevatu.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/j1690u5lqn7lqkqg636lsoj5if/13180940408.pdfIn PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/6ko2mjgj94fm5he13i93r6uf5i/zowov.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160894ecd6b519---rikibabajodezikokapupab.pdfIn PDF document text
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606d8b140165d---xepuporukififuviraforonuf.pdfIn PDF document text
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160d4052387025---48470060375.pdfIn PDF document text
    • https://gulertrafik.com/wp-content/plugins/super-forms/uploads/php/files/mukki09hpugn3a9dsnoil6juum/bovawidi.pdfIn PDF document text
    • http://richmore.kr/uploadfile/fckeditor/file/92846955410.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607768418b9d0---54407696603.pdfIn PDF document text
    • http://fullx.net/files/kezisaxudajamaxewopin.pdfIn PDF document text
    • http://bioterapiazabiegi.pl/obrazy/file/80959016812.pdfIn PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/160785d979ae8b---15493103369.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/16080ca73c226c---18174953003.pdfIn PDF document text
    • http://plastikacz.cz/soubory/files/90427139624.pdfIn PDF document text
    • http://safetypath.net/cms_images/jugekolowumeparerop.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160de8d2b273f9---88540298164.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1606d91b51b541---3636588496.pdfIn PDF document text
    • https://www.nrlandscapes.co.uk/wp-content/plugins/super-forms/uploads/php/files/a62795644907c49cab8fb1e3d043d74d/78644781062.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ada1fbc4d19---mugazanilipaj.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_off0000cb1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB1B 16848 bytes
SHA-256: b525d16d4058ea7a131a7b481f317297f4d619a5352d80dfbafa22142f828540
font_01_sfnt_off0000f5db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5DB 11412 bytes
SHA-256: ab150c901e7a25bba527d91df45336cb99882b5d492d471ef5cfc6a071402c01
font_02_sfnt_off00011027.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11027 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1