Malicious PDF — malware analysis report

Static analysis result for SHA-256 451bc2c9a598cbf8…

MALICIOUS

PDF

70.1 KB Created: 2021-09-14 01:20:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 5431decb8cc41dd7c0c7c218d7ecd611 SHA-1: 1cd356fa477937fa0b7107f661a4f75fa398d294 SHA-256: 451bc2c9a598cbf8a206fd491b7b5ef32c0baf953c65cbc7a2c7e0880437dc1a
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple websites, some of which are hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of numerous external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic suggest the primary goal is to redirect users to potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 https://medvor.ru/uplcv?utm_term=haruki+murakami+after+the+quake+pdf PDF link annotation
    • https://francois-daulte.com/ckfinder/userfiles/files/70502112744.pdfIn PDF document text
    • http://influences-vegetales.eu/assets/Image/files/52385829288.pdfIn PDF document text
    • http://teewer.mn/ckfinder/userfiles/files/51194965011.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/5f7gi9cf8qg15rl037o12mcmi7/sefonijedi.pdfIn PDF document text
    • http://stauarchitetti.eu/userfiles/files/zimituwiw.pdfIn PDF document text
    • http://elturo.ru/img/upload/files/8450364304.pdfIn PDF document text
    • https://loyd.rs/images/file/43656575456.pdfIn PDF document text
    • http://bonaparte-kerkrade.nl/fckeditor/ckfinder/userfiles/file/voluwuzo.pdfIn PDF document text
    • http://intersonik.eu/upload/files/nezutijoluvevufeboxabo.pdfIn PDF document text
    • http://kiko168.com/UploadFile/file/20210912232508913.pdfIn PDF document text
    • https://nepalihemp.com/ckfinder/userfiles/files/69247838904.pdfIn PDF document text
    • http://rainternacional.com/userfiles/file/wiwawovonipasefalokazu.pdfIn PDF document text
    • https://nicklason.se/ckfinder/userfiles/files/difojazuna.pdfIn PDF document text
    • http://orthodoxnews.us/file/28620645424.pdfIn PDF document text
    • http://imhyuk.com/imhyukeditor/userfile/file/70577892672.pdfIn PDF document text
    • https://yenhuy.vn/upload/files/vutufupowuxen.pdfIn PDF document text
    • https://aznamaste.com/ckfinder/userfiles/files/wugumezegaxemez.pdfIn PDF document text
    • http://tfforming.ru/d/files/kiladuwonutesat.pdfIn PDF document text
    • http://quaint-house.com/images/blog/file/porotowirijake.pdfIn PDF document text
    • http://contua.org/userfiles/file/57518202657.pdfIn PDF document text
    • https://art-lamps-rali.eu/files/file/janarojekonoki.pdfIn PDF document text
    • https://www.lindopoint.it/wp-content/plugins/super-forms/uploads/php/files/794c22525e1b4e4fd6c36d3d09a342cf/jojigelotogunav.pdfIn PDF document text
    • http://heilpraxis-pankow.de/wp-content/plugins/formcraft/file-upload/server/content/files/16135d8edede30---96811806498.pdfIn PDF document text
    • http://tsyrulnikov.ru/upload/file/riduxuwim.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_off0000af92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF92 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c7a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7A9 10656 bytes
SHA-256: 7f5ac9d4b76d4be32ebf8ac6bf4991d5a48ecdc7de7151b75e4389fbaf12b1da
font_02_sfnt_off0000dfc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFC5 17144 bytes
SHA-256: 1c69743a973c0a2c451bd2527630b079cadd1adfec768487fc038993eaddd0ea