Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f87c2c971ea7d68…

MALICIOUS

PDF

82.5 KB Created: 2021-09-01 04:58:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3b8c8322226429e2e5dab60ac565f3e4 SHA-1: 840774209a5fec4d4858505e1c4c091c9d438660 SHA-256: 8f87c2c971ea7d68b4e8b2ed55473618e90cb455069ea5322a40fcc36c0fd522
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and a machine learning classifier. It contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics indicate an attempt to lure users to potentially harmful sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9983

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 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.
  • 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://nomylo.ru/uplcv?utm_term=piratebay+sites+and+mirrors
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/cmra31ctdq5rrfp7brrd783992/89617497712.pdf
    • http://balone.net/_upload/file///vuburebovo.pdf
    • https://kovtec.pl/eurostyl/photos/file/35882861141.pdf
    • https://mattweidnerlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608720def226c---47898361457.pdf
    • http://di-tech.kr/fckeditor/userfiles/file/3903034786.pdf
    • https://unicornproduction.gr/wp-content/plugins/super-forms/uploads/php/files/62ad47e64c54d69c4b4a419d42949598/wesilexomadusudelun.pdf
    • http://libertyquad72.fr/userfiles/file/wosewowojapofijubexeremaf.pdf
    • http://starrsgazette.com/admin/images/file/faxipakizupajekeg.pdf
    • http://occahomesearch.com/userfiles/files/1301234018.pdf
    • http://virtuozi.ru/sites/all/sites/virtuozi.ru/files/97884064353.pdf
    • https://handinhand-daycare.com/ckfinder/userfiles/files/viwumuvujaz.pdf
    • http://pinzimoniofiumicino.eu/userfiles/files/wuxonavoxero.pdf
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/cn1usr4n0tj6anl3cs6g7u332i/leziruboxe.pdf
    • http://spearmanhsreunion.org/clients/e/e1/e1754705b4c076d7cd520c5e9e79ed07/File/ruzuxitadat.pdf
    • http://fujavietnam.com/images/Download/94420967956.pdf
    • http://abwva.com/uploads/files/13809514076.pdf
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/abjf32rickiab0ncfit12nbek7/40930592814.pdf
    • https://yingzhaoliuart.com/upload/file/90905547233.pdf
    • https://www.eoluk.com/wp-content/plugins/super-forms/uploads/php/files/e9ntk522s3jso6h759c1el9vrd/geramerunelufinebi.pdf
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/d586890a2a6e27349ce7c41904653201/4015315865.pdf
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/160cb8893c894c---dizuferamodifiwovubomaxaw.pdf
    • http://www.deopendeur.org/imgUser/file/64252291136.pdf
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/dfdj62aqg19cja2200j164db9b/64051446547.pdf
    • http://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/92822485198.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_off0000dff2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDFF2 16792 bytes
font_01_sfnt_off0000f804.bin
0ecc96f00b01a5ff7ed1ddb22d77fef545ffc1388a765e5e283c437317070e4f
pdf-font-stream PDF embedded font (sfnt) at offset 0xF804 16836 bytes
font_02_sfnt_off0001235f.bin
107f132d0ce9079c7e591afaca9b0c508750683a2ae16b7ab7f3be4357a4408c
pdf-font-stream PDF embedded font (sfnt) at offset 0x1235F 10616 bytes