Malicious PDF — malware analysis report

Static analysis result for SHA-256 4de41fed4018727f…

MALICIOUS

PDF

81.6 KB Created: 2021-09-09 16:49:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 8324cb752d2c1b26c234f94c9dad9821 SHA-1: 060d9c555f877556cc44c52affd11ac6e7518594 SHA-256: 4de41fed4018727f351cb5db0bbd39f91b2140dd5ac5d8cda902e269af2f7ca3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable domains, indicating a link farm designed to lure users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. The presence of 'utm_term' parameters in some URLs further supports a phishing or spamming campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://synerhu.ru/uplcv?utm_term=gramfree+apk+download PDF link annotation
    • http://kleinschadenexperte.de/userfiles/file/zetiruzubekuxekibisuduweg.pdfIn PDF document text
    • http://schoonhovensvrouwenkoor.nl/ckfinder/userfiles/files/joliw.pdfIn PDF document text
    • https://shinaltd.ru/images/file/96128612337.pdfIn PDF document text
    • https://drddvichitra.com/userfiles/file/50311697948.pdfIn PDF document text
    • http://ingore.cn/upload/files/zobevoperali.pdfIn PDF document text
    • http://alcantara.cz/data/file/56660810621.pdfIn PDF document text
    • http://studiogallerani.it/userfiles/files/97224713496.pdfIn PDF document text
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1613361e1457db---zedakesuto.pdfIn PDF document text
    • http://f-okinawa.com/img/tmp/files/kexavegesakawo.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/161305b7eabfd8---43769624128.pdfIn PDF document text
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/4b0fcf0be6f177d216bb3fb70e7cae71/tagutabotila.pdfIn PDF document text
    • http://arsvet.ru/img/upload/wufaguveviretokevisibefo.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/288ec6bb91c69ba4da6d6ed985cae8f3/wudixuv.pdfIn PDF document text
    • http://donghobaoan.com/uploads/files/zuvukasasagefubegor.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/16134bb2c0d987---64805560075.pdfIn PDF document text
    • http://svaz-podnikani.cz/files/file/1993633089.pdfIn PDF document text
    • http://skrn.cz/pic/file/5066917736.pdfIn PDF document text
    • http://guerrazzi.info/userfiles/files/jolokogugofulaxerawajaxis.pdfIn PDF document text
    • http://startent.ru/SITE/files/editor/file/tutifez.pdfIn PDF document text
    • https://sieuthimaycafe.vn/uploads/file/nigekipadir.pdfIn PDF document text
    • https://tpijobportal.com/ckeditor/ckfinder/userfiles/files/dobupakugosiwimepezejaweb.pdfIn PDF document text
    • https://alutat.com/data/file/18641924258.pdfIn PDF document text
    • http://sage-chem.com/image/files/20210908_150034.pdfIn PDF document text
    • http://factorycontrolprojects.com/userfiles/file/tozawomapagixokipozudesi.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_off0000d94c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD94C 10516 bytes
SHA-256: 292a312d8b85084e3dced5cb1dbfa4d758eb2cf0486ff090fbd53a944b369d0a
font_01_sfnt_off0000f142.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF142 18264 bytes
SHA-256: e1410103caa6415e4ccd499db88a634b72d8678c6e55232f0cce54fff8172459
font_02_sfnt_off000120c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120C2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1