Malicious PDF — malware analysis report

Static analysis result for SHA-256 e5888138c6da54ed…

MALICIOUS

PDF

87.4 KB Created: 2021-09-04 22:19:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 0ec16354009d5d245b18e3559f4b35af SHA-1: 3f4eb97c557d748c94107dc0d2c5d4470c302093 SHA-256: e5888138c6da54ed461ba639ca4675ac709555c31dc7fe265ebdcb76ce14f236
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, containing numerous URLs pointing to various websites, some of which are hosted on compromised CMS upload directories. This suggests the PDF is likely used for SEO poisoning or to redirect users to malicious sites.

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 http://vladekoservis.ru/files/79804081200.pdf In PDF document text
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/f8772a666f524c4c9f868d48f809732e/majiliteloxilojifik.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0ddde6a814---88923763822.pdfIn PDF document text
    • http://altaprecision.com/userfiles/file/6662012777.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/955414059fa914171b15786d34303d74/33244715127.pdfIn PDF document text
    • http://otohyundaidanang.com/uploads/image/files/55876713572.pdfIn PDF document text
    • http://derkwoo.com/upload/editor/files/tufazisinibiwaluteziz.pdfIn PDF document text
    • https://aradmissions.com/ci/userfiles/files/88991462550.pdfIn PDF document text
    • https://cape-electronics.com/media/file/41889276510.pdfIn PDF document text
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/4775a5455d660854347e43c0d2795cec/92242499640.pdfIn PDF document text
    • https://www.picmephotoboothhire.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160918b4430234---27754075361.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/161185a5f42162---jozox.pdfIn PDF document text
    • http://sghr.ca/upload/ckfinder/files/58513355727.pdfIn PDF document text
    • http://china-engine.net/ckfinder/userfiles/files/tuber.pdfIn PDF document text
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/1611a9f1e3fe83---39888929926.pdfIn PDF document text
    • https://club-sports.net/uploads/products/files/vekonoxo.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/jpdmfdnbbr2q4j39a2rs63kgg7/retejezunonevegunizinegal.pdfIn PDF document text
    • http://coreaad.com/DreamDataUpload/file/xunutojo.pdfIn PDF document text
    • http://luckdidea.com/ckfinder/images_store/files/munonosukujenumomufosid.pdfIn PDF document text
    • http://librojuridico.com/aym_images/files/3224490116.pdfIn PDF document text
    • https://artbynela.com/uploads/file/wudulum.pdfIn PDF document text
    • http://rmgoals.com/userfiles/files/kegigon.pdfIn PDF document text
    • https://adepotcustom.com/UploadFiles/file/20210504090339142.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/kk4rjr6ula34i914bevk9mrk30/41592497825.pdfIn PDF document text
    • http://de-ko-gmbh.com/ckfinder/userfiles/files/85235774527.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=graphing+rational+functions+worksheet+honors+algebra+2+answersPDF 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_off0000e9f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9F2 11336 bytes
SHA-256: 76a56dc28043f63117d310423ebc314873f8c7cce1d6749e3d9fd52178444166
font_01_sfnt_off00010482.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10482 18668 bytes
SHA-256: ef49693c8631d08116b84618648237c1ea406b3ee93af8aaf9ecef4983002cfb
font_02_sfnt_off0001352f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1352F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1