Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d5612c971227145…

MALICIOUS

PDF

80.2 KB Created: 2021-09-20 03:33:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c17f46d1bd828dde11d385afa13a4f6c SHA-1: bb5f9fe2b9cb149e451b51d3052153bed28842d8 SHA-256: 8d5612c9712271457ca2c9dd04b5cb581b4a3ffa1933569897ca17f35db01468
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF containing embedded JavaScript, which is a common technique for exploiting PDF vulnerabilities or delivering malicious content. Heuristics indicate it functions as a link farm, directing users to multiple external PDF files hosted on potentially compromised or disposable domains. ClamAV and ML classifiers confirm its malicious nature, specifically flagging it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://festival.bg/fckeditorfiles/file/36896308986.pdf In PDF document text
    • https://pinkrali.com/calisma2/files/uploads/67801842873.pdfIn PDF document text
    • http://jedzenie365.pl/ckfinder/userfiles/files/24504514043.pdfIn PDF document text
    • http://ddservice-bmw.pl/userfiles/file/xajovujejapavudoxopire.pdfIn PDF document text
    • http://bezagsecurity.cz/userfiles/89038053145.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613e85bd109f8---85759742765.pdfIn PDF document text
    • https://xn--bankkrtya-41a.hu/js/ckfinder/userfiles/files/pupurazepoboliwidaxuzoseg.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144b4bcc528a---zakeja.pdfIn PDF document text
    • http://seychelles-resort.com/images/blog/file/14261626462.pdfIn PDF document text
    • https://valve-toho.com/userfiles/file/2679013771.pdfIn PDF document text
    • http://zhfangyuan.com/uploadfiles/files/xosawivilot.pdfIn PDF document text
    • http://fourfoods.com/images/files/xadidakusitijotas.pdfIn PDF document text
    • https://anakmeong.com/contents/files/21942550708.pdfIn PDF document text
    • https://rrr71.ru/upload_picture/zonadowiboni.pdfIn PDF document text
    • http://inica.org/files/file///jidavomivajijafesuvovemi.pdfIn PDF document text
    • http://tiyuchangdi.com/upload_files/files/20210913_080449.pdfIn PDF document text
    • http://www.plain-pied.com/editeur/ckfinder/userfiles/files/zuvikekosuxataduxuboro.pdfIn PDF document text
    • http://bong-dem-long.org/upload/editor/files/kukar.pdfIn PDF document text
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/q99788inkrv2dfhrg76iur93ac/9458743273.pdfIn PDF document text
    • https://vidaleve.ind.br/ckfinder/userfiles/files/89308438939.pdfIn PDF document text
    • http://www.chatanakonci.cz/userfiles/file/67520588345.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=how+to+recover+deleted+screen+recording+videos+androidPDF 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_off0000d55d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD55D 10688 bytes
SHA-256: 02db8c92b5b2fad42cf818d3960fdf67b3123e5cd66f3c37b7c5d613fd53b19a
font_01_sfnt_off0000edcc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDCC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000105de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105DE 17432 bytes
SHA-256: 8a60dc7b51c0f60fd3dca32a00309733224390424221f99699354531c9ef1cc9