Malicious PDF — malware analysis report

Static analysis result for SHA-256 1cf36d522930a6e2…

MALICIOUS

PDF

77.8 KB Created: 2021-09-19 14:46:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: cb75202d5c1ed02ba31350fe7cce9522 SHA-1: 056ecf74dfa1fc0ad7bc57e98de4cd2e8dab1c3c SHA-256: 1cf36d522930a6e2e0226588942e9866144820e7080c4bd2403c3d8aec267d0a
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically identified as a phishing or trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS platforms or disposable domains. The presence of numerous unknown URLs suggests an attempt to distribute malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://gradn.ru/uploades/fckeditorfile/wenagukajanovot.pdf In PDF document text
    • https://schachverein-marchhoefe.ch/fcsr/news/upload/file/wejapunebisudinizeli.pdfIn PDF document text
    • http://mzch.pl/userfiles/file/rexebar.pdfIn PDF document text
    • https://sistemagestiondpr.co/userfiles/file/89134013099.pdfIn PDF document text
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136fca03a2dc---86536033987.pdfIn PDF document text
    • http://yearbookplus.com/uploads/ckfinder/files/54854417610.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e0812beb02---41077893501.pdfIn PDF document text
    • http://aaas.handyfriendship.com/upload/files/bexoxaf.pdfIn PDF document text
    • https://neurondevelopment.org/userfiles/file/fikagor.pdfIn PDF document text
    • https://hediyelikhanem.com/calisma2/files/uploads/11406018601.pdfIn PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/c8fsids9hgn3bqjr2nqlkr7lim/5084090197.pdfIn PDF document text
    • https://tainandentist.com/uploads/files/202109111457357256.pdfIn PDF document text
    • http://obkladacstvikolar.com/content/30531842652.pdfIn PDF document text
    • http://launensia.cz/ckfinder/userfiles/files/98407371369.pdfIn PDF document text
    • https://hongmao.tw/uploads/files/202109092112034111.pdfIn PDF document text
    • http://german-ex.com/images/blog/file/nuboso.pdfIn PDF document text
    • https://bahamianbrewery.com/ckfinder/userfiles/files/28126508155.pdfIn PDF document text
    • http://thaisomboonautopart.com/userfiles/files/nidapedexubetovojoput.pdfIn PDF document text
    • http://jungam21.com/upfiles/file/1631592996.pdfIn PDF document text
    • http://harekatmemuru.com/images/Media/files/34095811652.pdfIn PDF document text
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/domit.pdfIn PDF document text
    • https://shevtsov-art.com/uploads/files/47782085100.pdfIn PDF document text
    • http://dgxzz.com/uploadfile/file/49499686411.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=how+to+connect+mobile+as+webcamPDF 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_off0000cd7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD7F 10508 bytes
SHA-256: da958bd1f7bafa41c6ebbc193201dffcf6560246f423eb6933bed6f6d2683bb7
font_01_sfnt_off0000e566.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE566 17120 bytes
SHA-256: efacd6247cd99b94d44d508cb048af131bfe9b7aa39b28a35494d43e511d26b1
font_02_sfnt_off000111d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111D1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1