Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d61c140bea0a504…

MALICIOUS

PDF

85.1 KB Created: 2021-08-08 22:54:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 89118ff74a5111f0e603b7ecaeaf303c SHA-1: 5efb597946098156a8c47a35e0ca07968c70929e SHA-256: 8d61c140bea0a50470fd5e77093c27c3395ddc1ba5d7693a696d403aa54778c0
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites acting as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The presence of link farms suggests an attempt to obscure the final destination and evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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://piqiso.ru/userfiles/file/32497521072.pdf
    • http://yuhongzg.com/d/files/55682934818.pdf
    • https://argumentua.com/i/file/duvabesiku.pdf
    • http://www.heksan.com.pl/file/tazafusawixerut.pdf
    • https://fastcomputer.vn/wp-content/plugins/super-forms/uploads/php/files/549c4b6c995216cb11d9df3a442feb65/vimexorawalasipav.pdf
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b04c54cfc9e---44772287804.pdf
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/0248e5fe121f1f9e23b5ecc060f6687d/wenew.pdf
    • https://cwlighting.com/wp-content/plugins/super-forms/uploads/php/files/77b35c2c46c3967a5f771d39c6ed11c9/bewixugufitamisawivo.pdf
    • https://mongolia-volkslift.com/uploads/files/96310766638.pdf
    • http://hoitruyengiaocodocvietnam.com/uploads/image/files/79834395277.pdf
    • https://barcelonacentremedic.cat/files/galeria/files/nulum.pdf
    • https://techson-cctv.com/upload/file/93779401602.pdf
    • http://savitapiti.org/ckfinder/userfiles/files/57953423937.pdf
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a21c3aace6---dilosokataf.pdf
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607d61d2ca59d---fawutikidug.pdf
    • http://apsons.eu/files/file/70456507982.pdf
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607d1fdc9ad0d---88404977050.pdf
    • http://www.lifestaralberta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608395675a0c8---95317874097.pdf
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b5fcf6a96c---97998592141.pdf
    • https://efnnma.org/files/file/gimanoxaladakeri.pdf
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af7e703c301---ponawijirade.pdf
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4374b42bbd---wewatogimav.pdf
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fa3620a739---63798175608.pdf
    • http://allamericannursing.com/userfiles/file/gumiwilowevoratog.pdf
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/36cebe92ec1c9487426d086c68b9105c/nuruveka.pdf
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d3227e2e7e---86513831738.pdf
    • http://www.jeddaandrews.com/download/cat-143h-motor-grader-
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=cat+140h+grader+service+manual
    • 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_off0000e5c7.bin
300d138eb47b50274d1f5febf933f4f4d84c8d9e457eb40bc47004a924bdf67a
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5C7 11144 bytes
font_01_sfnt_off0000ff96.bin
0bd7aafda66f85ff124003aaba13027135ec2ec09a6995a46137a21ec9a292de
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF96 17528 bytes
font_02_sfnt_off00012e0b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E0B 16792 bytes