Malicious PDF — malware analysis report

Static analysis result for SHA-256 f6ec9bceeff27b90…

MALICIOUS

PDF

86.9 KB Created: 2021-07-02 18:21:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 327f9dc469e24801e16d548568248e41 SHA-1: 9dcac35ddf2b433f9636531f0d9d9dd2efac166d SHA-256: f6ec9bceeff27b900876390be2ad086391ac180f9626b557ef82fc9d04fbc2f3
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Numerous heuristics identified the PDF as a link farm, with many links pointing to compromised WordPress upload directories. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://lose-weight.tw/upload/files/fobiveretefuluziwus.pdf
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad524687cca---77631923115.pdf
    • http://fra2ange.it/userfiles/files/45734868182.pdf
    • http://ar-intl.net/wp-content/plugins/super-forms/uploads/php/files/247olhlqs7n576p2u9ve4i5pk6/29397039596.pdf
    • https://www.nosolodespedidas.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608235a379333---kizolonawifojekis.pdf
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/bc36ea6ed1c876935f33082bf0d3e391/fibej.pdf
    • https://jennysbooks.com/wp-content/plugins/super-forms/uploads/php/files/228c730e0e4371a55c2a63a4d0c49dfb/50877615665.pdf
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/a6bdde39a5a27681e8a8731c25a5c86f/57647526753.pdf
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608888c27114e---pasitop.pdf
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/160cf26223ab39---laboruwatezalafeji.pdf
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/o5se23ia07v42rndj7d1c26g24/xubumexofutirulon.pdf
    • https://airflow-skateboards.com/userfiles/files/gawozomuna.pdf
    • http://orgue-chantepie.info/FCKeditor/upload/file/vefelekoliwobun.pdf
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/16087d9825dba2---13960891009.pdf
    • http://starcity-vinhomes.vn/app/webroot/img/files/gisuwuvirejoxowu.pdf
    • http://mextro.de/upload/files/25026206188.pdf
    • http://softwarefactory.nl/images/file/38386180761.pdf
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/160b040c1a27f4---56462964131.pdf
    • https://greshamgilessalon.com/wp-content/plugins/super-forms/uploads/php/files/107ad8124f14eb67abf5478e7f56c5f8/wunofedefig.pdf
    • https://fmpride.com/wp-content/plugins/super-forms/uploads/php/files/dd80f9a80cc31a2c1cf2413addb08893/rasojokiw.pdf
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/9a722caa41cf3bbd40f6d9a8870d4aec/fuvanev.pdf
    • http://ajivikafinance.com/userfiles/file/68479705688.pdf
    • http://hillcountryawningsandsunscreens.com/wp-content/plugins/formcraft/file-upload/server/content/files/160858f158e26e---33781681247.pdf
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/8ee694c097cb8a362964ff294a837abb/52929194126.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=35+divided+by+100
    • 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_off0000f31a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF31A 16792 bytes
font_01_sfnt_off00010b31.bin
63fbf9c4b8e77cbf4933b1b259b07540153d458cc54a3b9a1663fdc096a58f29
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B31 10148 bytes
font_02_sfnt_off000121f8.bin
33ecb2bc8a07f14bec5a52dae6349140b35f1fba775d2db960497fcc1a66bb10
pdf-font-stream PDF embedded font (sfnt) at offset 0x121F8 17076 bytes