Malicious PDF — malware analysis report

Static analysis result for SHA-256 1bf8ab7a7a119d24…

MALICIOUS

PDF

100.2 KB Created: 2021-07-19 19:12:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 95482a40d9b178cb52aa74dae0cbdb2a SHA-1: 1b1daea5e667abe0cf81988d844f9357bf80b8b5 SHA-256: 1bf8ab7a7a119d248cd960eee858f39286c61160c0d27e8a3125d7cefdda31ac
156 Risk Score

Malware Insights

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

The PDF document was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised CMS upload storage, suggesting it functions as a link farm to distribute malicious content or phish users. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9800

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://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/8040758f9e21db23dbfe1ea85f4815c8/gisoz.pdf In PDF document text
    • http://eko-inwest.eu/upload/file/fuxoxixajagixadilokux.pdfIn PDF document text
    • https://forex-robo.org/wp-content/plugins/super-forms/uploads/php/files/a407e068137d33ec744452f4ea624df4/62356544577.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095e484e8417---85390846111.pdfIn PDF document text
    • https://amd-export.com/site/upload/file/mugekobazagovem.pdfIn PDF document text
    • https://wecafephuket.com/wp-content/plugins/super-forms/uploads/php/files/ljpjh5chdm10l5gafqjmnv42lq/jarirutodemef.pdfIn PDF document text
    • http://ks-puyuma.com/CKEdit/upload/files/vavodovuwijawufatujulanav.pdfIn PDF document text
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609d5046e5ebd---54471325858.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607cdda0a475e---sozobosebujumod.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/160ae3802cb4dc---68534616453.pdfIn PDF document text
    • http://thepnguyentran.com/media/ftp/file/93646230634.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a99889beb55---zosizowuwogitot.pdfIn PDF document text
    • https://bosingels.nl/ckfinder/userfiles/files/13818404141.pdfIn PDF document text
    • https://www.ltgpartners.com/wp-content/plugins/super-forms/uploads/php/files/9b9397cb651931d119b525c18ebac542/58617704297.pdfIn PDF document text
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/160849d85f2bce---68740500223.pdfIn PDF document text
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/6hp4nemjhlhg84qgd6cs1gkmm3/78232049417.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a5889b324ce---1079539961.pdfIn PDF document text
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606f6bdec8556---kibaketiwutupu.pdfIn PDF document text
    • https://movesforfree.com/wp-content/plugins/super-forms/uploads/php/files/k2cv6k4qd6dl5of4epk4ic83o6/suxiruzejelurajuva.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608f61d463f7e---gopalewu.pdfIn PDF document text
    • http://mispuntossaga.com/campannas/file/pabipujesipavilokulafodi.pdfIn PDF document text
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/1fe1b65c45135be6cf18799673115e94/82910163278.pdfIn PDF document text
    • http://eortak.com/img/fck_temp/file/20973766979.pdfIn PDF document text
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9e7011cdbe---mizoxagabovonifed.pdfIn PDF document text
    • http://stellamaris.cz/userfiles/36805972933.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160d513ff8539e---65810329720.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=alabama+learner%27s+permit+bookPDF 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_off0001141a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1141A 24200 bytes
SHA-256: 7fc5dd0f27c20369fd6b3238e6faea98809baf8d63212a0c66587943ff58b3c0
font_01_sfnt_off00015172.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15172 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00016989.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16989 10660 bytes
SHA-256: eb2f800527ae11e4c406e20c58c5b5c68ffa7130c1a3e912f07ff5bc39f20df5