Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc837585f3ea7ae2…

MALICIOUS

PDF

112.2 KB Created: 2021-07-14 05:17:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: aa86cf60147895c1eaa3af0a8098391e SHA-1: fef4244a56dd4f0efcc05f645dd476af2f7e015f SHA-256: bc837585f3ea7ae29232c88aff07939b6e601a45484d46cfbc0fc813d361b5fd
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting it functions as a link farm. The primary purpose appears to be directing users to external malicious sites, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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://krisoc.ru/uplcv?utm_term=mutual+discourse+meaning
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607aac91c69d1---xipidovanakonesobux.pdf
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b363931f50---41026000714.pdf
    • http://dexgerm.com/data/file/userfiles/files/jazupi.pdf
    • http://portalpr-b2b.es/img/user///file/_0529894001625335860.pdf
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160a407a0c641f---6602771154.pdf
    • http://delannahotel.com/user_img/file/kiwomugefawafojexoxole.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607b09af83283---28623545267.pdf
    • http://panyuchen.com/ckfinder/userfiles/site_eachfun_com/files/pifebewejibopewe.pdf
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/32e7b2a25f4699edf76bbc472d80ef17/bokezaferes.pdf
    • https://aradovan.com/userfiles/file/40005417777.pdf
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c92e92efdb4---6425177002.pdf
    • https://benchmarktransitions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a88abfa8254---74204583247.pdf
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/35c3b491ffb16a1c2269d4f9c689e6a5/rofewijenitifexen.pdf
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/eej564bj559d35m5vh77k6c987/50937122873.pdf
    • http://ngpsusa.com/wp-content/plugins/super-forms/uploads/php/files/qgbpk41c75uv1veh5ia9vlrhuf/kexikezemiliz.pdf
    • http://premium-h.info/files/files/bididepisuwe.pdf
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a899fe19b6---22857331483.pdf
    • https://vibangthuaphatlai.net/uploads/files/99211809654.pdf
    • http://gapoom.com/upload/fckeditor/file/bewegut.pdf
    • https://thaihoanghung.com/upload/files/kanikufasebagefitekinedav.pdf
    • http://petersonspann.com/clients/3/32/32c4b2f41fa698b5b938e848169c8dcb/File/kozowedatevufer.pdf
    • http://dokturmice.com/ckfinder/userfiles/files/ziforelewab.pdf
    • http://euroinstytut.pl/galeria/file/28826096999.pdf
    • http://kiavysocina.cz/UserFiles/File/43118362987.pdf
    • http://veterani-pushkino.ru/userfiles/files/didiwaxugovorasox.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_off0001504f.bin
c6cd9af0faa105402704023ac6bf575a379b3cf19672f5d087eea595c9edcbbc
pdf-font-stream PDF embedded font (sfnt) at offset 0x1504F 10804 bytes
font_01_sfnt_off000168fd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x168FD 16792 bytes
font_02_sfnt_off0001810f.bin
586a70113d182699a999de0483e0874bdddc2c25926df6a28273983244962a0d
pdf-font-stream PDF embedded font (sfnt) at offset 0x1810F 19108 bytes