Malicious PDF — malware analysis report

Static analysis result for SHA-256 ae10388e311842fb…

MALICIOUS

PDF

84.0 KB Created: 2021-09-19 03:55:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7209d57155039f1f86d43073665121d3 SHA-1: 90e05cd401d0f990bc2869e828c47ec06a469c20 SHA-256: ae10388e311842fb2b12a03374603317bec0d36a86ceeb771d81cf5cc5f310ca
204 Risk Score

Malware Insights

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

This PDF sample contains embedded JavaScript and multiple links pointing to external resources, many of which are hosted on compromised WordPress sites or disposable domains. The heuristic firings indicate a link farm designed to redirect users to potentially malicious PDF files, suggesting an attempt to download and execute a second-stage payload. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 8

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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 http://yacpa.org/yacpafiles/file/lofexukukagagifov.pdf
    • http://studiopol.com/userfiles/files/67607623317.pdf
    • http://ambulatorioveterinarioscapindandrea.it/userfiles/files/96588206030.pdf
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/161409416e7e17---8910116000.pdf
    • http://belly.bpv.su/content/files/files/legozoraguxutu.pdf
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143cab96430a---11181541751.pdf
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613a35fab418f---65223072756.pdf
    • http://labuchedeberce.fr/userfiles/file/92787962104.pdf
    • https://www.tahitotfalu.hu/ckfinder/userfiles/files/fuduzus.pdf
    • https://xo-sound.ru/userfiles/file/raliwolopotosag.pdf
    • https://onderdurdu.com/upload/ckfinder/files/gikegutujevudakosawikib.pdf
    • http://msnladyboy.com/ckfinder/userfiles/files/57172414871.pdf
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/161370871787b8---xefawij.pdf
    • http://medwin.kr/userData/board/file/rarelibijejasaleg.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161425ef8501d3---2919506603.pdf
    • https://infypos.com/infyposcms/media/naxijum.pdf
    • http://ecole-belair.com/ecole/file/buzosudefusozujofamufare.pdf
    • http://optykglowacki.pl/obrazki/files/22984192263.pdf
    • http://davidhammerstein.org/ckfinder/userfiles/files/91108399599.pdf
    • https://ooo-kenk.ru/userfiles/file/jugemajutezi.pdf
    • https://www.fishhabitatnetwork.com.au/application/third_party/ckfinder/userfiles/files/10591449732.pdf
    • http://klick-tipp.at/ckfinder/userfiles/publics/files/26950668243.pdf
    • https://apaman.ti-am.jp/js/ckfinder/userfiles/files/52768190568.pdf
    • http://jullien38.com/ressource/site-image/files/43327757089.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=test+para+detectar+dislexia+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e13c.bin
024a85ee035605b19e7151f947fefa438196c5cb3b964bcb6ef04b5ce6c3925b
pdf-font-stream PDF embedded font (sfnt) at offset 0xE13C 10452 bytes
font_01_sfnt_off0000f917.bin
ae803717cb005fe00e5c29c06987f55d08e60e33f8b02ebcdff819fcd553b11d
pdf-font-stream PDF embedded font (sfnt) at offset 0xF917 18796 bytes
font_02_sfnt_off00012a1b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12A1B 16792 bytes