Malicious PDF — malware analysis report

Static analysis result for SHA-256 f84c1a8772b45f72…

MALICIOUS

PDF

76.9 KB Created: 2021-10-08 01:16:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: cb846d9aba573e4b6b0b629019912153 SHA-1: 1ef76dccd4492a0578add3fa19ad347f0908e175 SHA-256: f84c1a8772b45f72c3a776bf3a03daad1974d111c0ae4110c14adc19768930c6
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. ClamAV and ML classifiers flagged this PDF as malicious, specifically as a phishing trojan. The presence of numerous unknown URLs suggests a broad attempt to lure victims to potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 6

  • 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.
  • 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://scales-center.com/shop/fck_file/file/51164332592.pdf In PDF document text
    • https://hoanghaie.com/Images_upload/files/pajurexukunir.pdfIn PDF document text
    • https://luathoanghuy.com/uploads/files/40088691939.pdfIn PDF document text
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614906adca229---besaragi.pdfIn PDF document text
    • https://immsac.pe/sgi_userfiles/userfiles/files/96931496577.pdfIn PDF document text
    • https://alutat.com/data/file/vugokirelekejozeton.pdfIn PDF document text
    • http://sjatupornservices.com/file_media/file_image/file/57247233043.pdfIn PDF document text
    • http://tentauto23.ru/ckfinder/userfiles/files/kimupevutubupekogexudopak.pdfIn PDF document text
    • http://nedvizhimost-v-sharm-el-sheikhe.ru/uploads/files/63744007505.pdfIn PDF document text
    • http://khautrangkhangviet.com/upload/img/files/29287947666.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16138df0a90e42---lesegobaxumewigaletozom.pdfIn PDF document text
    • http://hmsendo.pl/uploads/editor/file/jupojutubawenaziwoxulexu.pdfIn PDF document text
    • http://solarexperte.ch/fckeditor/editor/images/file/vukamutetusulasewor.pdfIn PDF document text
    • http://moriefrusca.com/userfiles/files/damakimoru.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614f2e42d0673---70872911523.pdfIn PDF document text
    • https://stpm-sa.com/userfiles/file/74334178207.pdfIn PDF document text
    • https://affordans.com/ckfinder/userfiles/files/budebovanudig.pdfIn PDF document text
    • https://salvamontbihor.ro/app/webroot/files/userfiles/files/41614087539.pdfIn PDF document text
    • http://yanartekstil.com/firma/files/lifolatu.pdfIn PDF document text
    • http://historico.uts.edu.co/portal/app/ckfinder/userfiles/files/14509636092.pdfIn PDF document text
    • https://a2designbg.com/userfiles/file/vitamukikemixevotiviw.pdfIn PDF document text
    • https://ketex.com/trcgp/ckfinder/userfiles/files/debagapuziziginebewes.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/ln8dtn6fni4vfbpn0sd1bqs41i/metegixade.pdfIn PDF document text
    • http://dentalweek.eu/userfiles/files/31978418377.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=thermostable+alpha+amylasePDF 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_off0000c940.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC940 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e152.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE152 17312 bytes
SHA-256: 93dfcc84adb6f364d7faecdec17558b60795572f1ec2ade26c57c570cdda8dbc
font_02_sfnt_off00010e44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E44 10536 bytes
SHA-256: 23dbbe0ad427a6f1eedba375f18f06bc0bbc49510b921d41fd33c3ee5e6f4723