Malicious PDF — malware analysis report

Static analysis result for SHA-256 f3a6503838737aaa…

MALICIOUS

PDF

74.1 KB Created: 2021-09-17 15:59:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: bcd1ebd8182fff761db3fe11fb2d04bc SHA-1: 89c5ca489b5d174244007e5792c163b8215785ca SHA-256: f3a6503838737aaa5e32e1c60901ccbb64d333b93e2a316b4aeb6ae5d7f25b30
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm hosted on disposable domains and compromised WordPress uploads, suggesting a phishing or malware distribution lure. Although no scripts were explicitly extracted, the PDF structure and embedded URLs point towards an attempt to redirect users to external malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://allytemp.ru/uplcv?utm_term=solutions+manual+fluid+mechanics+fifth+edition PDF link annotation
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/ed76c54518babc5c68480654331393db/21133199401.pdfIn PDF document text
    • http://zhfangyuan.com/uploadfiles/files/popidawarobas.pdfIn PDF document text
    • http://www.serge-valentin.net/ckfinder/userfiles/files/92326620324.pdfIn PDF document text
    • https://speak82.com/_UploadFile/Images/file/vijebasatisazoro.pdfIn PDF document text
    • http://triple-a.co.th/ckfinder/userfiles/files/38002351461.pdfIn PDF document text
    • http://vnationwide.com/userfiles/files/42572875717.pdfIn PDF document text
    • http://kbidc.kr/upload/editor/file/1631118933.pdfIn PDF document text
    • http://sangtaoad.com/uploads/userfiles/file/37403463221.pdfIn PDF document text
    • https://cuatudongnhatrang.com/uploads/files/fozew.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1613f801909e91---jajapajufe.pdfIn PDF document text
    • http://vattucongtrinh.com/userfiles/file/jezegafagugalifegozarew.pdfIn PDF document text
    • http://restauraceeverest.cz/userfiles/file/84001010285.pdfIn PDF document text
    • http://ricarda-allegra.de/userfiles/file/27092521790.pdfIn PDF document text
    • http://slenderclub.cz/ckfinder/userfiles/files/tuxibudexitizoduwawivis.pdfIn PDF document text
    • http://mini-garden.ru/userfiles/file/73531636839.pdfIn PDF document text
    • http://tractortools.cz/ckfinder/userfiles/files/vufesakojogejobitavidoja.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139f20ebd7cc---nodulonitovafumowimune.pdfIn PDF document text
    • https://tbsva.org/Upload/files/20210907224437.pdfIn PDF document text
    • https://peptidturkiye.com/ckfinder/userfiles/files/92573185806.pdfIn PDF document text
    • http://gamjagolla.com/uploads/files/44359631519.pdfIn PDF document text
    • http://spielundlicht.de/content_provider/documents/files/56738383091.pdfIn PDF document text
    • http://portakalweb.net/home/portakal/public_html/ckfinder/userfiles/files/kerisofunekamewejewuvobi.pdfIn PDF document text
    • http://kpghomerepairs.com/uploads/image/files/bikalawazijiwakozamivopi.pdfIn PDF document text
    • https://datatalk.ilvzhou.com/upload/files/2021/09/202109101143483230.pdfIn PDF document text
    • http://royalrep.com/userfiles/files/fewipopaxalos.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_off0000bec5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBEC5 17004 bytes
SHA-256: 2b8248ee154c64a47dd5409f7fc21dcde7bbc3a427f3fcdb4e085417a6006ba8
font_01_sfnt_off0000e986.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE986 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001019d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1019D 10816 bytes
SHA-256: 67362c5534d808d7f3a8da68655b0d130dd78cf20924d4201eca462bb081662b