Malicious PDF — malware analysis report

Static analysis result for SHA-256 316c9d64a34400d9…

MALICIOUS

PDF

79.9 KB Created: 2021-09-16 16:36:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: bde660d753a45c6961c4765b9bf048d1 SHA-1: 74f18649b5de299fb0abb41828b7494710d1bfae SHA-256: 316c9d64a34400d98654bbe0459e2b60093bed8708b4582777afcbea32f7eed4
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and a link farm. The embedded JavaScript likely facilitates malicious actions, such as downloading further payloads or redirecting the user. The link farm, composed of numerous URLs pointing to potentially compromised CMS uploads and disposable hosting, suggests an attempt to obscure the final malicious destination and evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://huntic.ru/uplcv?utm_term=how+to+setup+apk+file+on+android PDF link annotation
    • https://dunaweb.co/bg_image/files/84607530621.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613954f924546---96227844049.pdfIn PDF document text
    • https://taiwancy.com/app/webroot/userfiles/files/tivexofurudexoguxoxew.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1613fbff4ad1cc---saxutasowoduwefubibuguxu.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/llvuiq4el20bla52gej7k2o5t4/75173595729.pdfIn PDF document text
    • https://brahmagnanam.org/fck_uploads/file/32072082897.pdfIn PDF document text
    • https://edinburghpools.com/contents/files/50275752757.pdfIn PDF document text
    • https://ginniglobal.com/uploads/file/kurifedefe.pdfIn PDF document text
    • http://moretonassets.net/userfiles/91990538207.pdfIn PDF document text
    • http://www.performhabitat.fr/bundles/astadmin/js/ckfinder/userfiles/files/nasopafezozaweg.pdfIn PDF document text
    • http://munnarteabungalows.com/userfiles/file/gulojenusibokenopen.pdfIn PDF document text
    • https://parfumzone.ro/files/file/83145045172.pdfIn PDF document text
    • https://generalaudit.pl/eurostyl/photos/file/sudadiwafakolamuvukef.pdfIn PDF document text
    • https://landtop.com/filespath/files/20210909151045.pdfIn PDF document text
    • http://pinxedien.net/upload/files/74901504896.pdfIn PDF document text
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/4011d631894ed17e8ee4a56bffa6b712/24971611622.pdfIn PDF document text
    • https://akemi.ro/hirek/file/gufupexofafezowuviliwovis.pdfIn PDF document text
    • http://h-st.nl/bestanden/files/detijatigexafarola.pdfIn PDF document text
    • https://carsen.sk/editor_uploads/system/files/12744123831.pdfIn PDF document text
    • https://nordavril.com/userfiles/file/65718291082.pdfIn PDF document text
    • http://transchem-tech.com/Uploadfiles/files/surufonorozunuwe.pdfIn PDF document text
    • https://muachungbaohiem.com/uploads/userfiles/file/90142170221.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_off0000d480.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD480 17256 bytes
SHA-256: 01861e5be05314c405ea07effae418299a709ed2f78e2e7022e9e068a841af86
font_01_sfnt_off0001010a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1010A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011921.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11921 10760 bytes
SHA-256: d04f0125b05184750cfc73e87fadc004f8220da92214a106b95cb32bd66bb88b