Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a7bf0c052e66aa1…

MALICIOUS

PDF

88.3 KB Created: 2021-08-27 10:57:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: cc8c48a0c49bcb38d88554e032608941 SHA-1: ffb0f0189f37d273afc4c4eafc571b58d9f0bb55 SHA-256: 9a7bf0c052e66aa11b10dbe7c2ecc6ba6da2e797b4f46a7a6f6479b2a2626ca5
156 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains numerous links, many pointing to compromised WordPress upload storage and disposable hosting, indicating a link farm designed to redirect users to malicious content. 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 vehicle for the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9764

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606d27fc2b8f4---senapukofare.pdf In PDF document text
    • http://fireprovietnam.net/luutru/files/28178794542.pdfIn PDF document text
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/jdtahhalln1jme3r51lsicakd5/vofawivarawujugaxulelit.pdfIn PDF document text
    • https://ndmoyun.com/calisma2/files/uploads/refilagukesovemivasuzive.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/ibj3qq6v9d6opfev9khiejnek6/popatatuwirerimeg.pdfIn PDF document text
    • http://oreoltour.ru/sites/default/files/file/zexita.pdfIn PDF document text
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/mhj94hfhfbb3t58jac5045jnc2/lezoxezamewimu.pdfIn PDF document text
    • http://setadijital.com/img/userfiles/files/kinebodivorizolinexun.pdfIn PDF document text
    • http://tuzvedo.hu/elemek/file/54274975368.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/shmtop4crevcg6jk8ojt4bv9q6/45457970081.pdfIn PDF document text
    • http://arniestribu.com/campannas/file/xomevenofojiretasa.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/a9ac8c38e9c4363b74b5e48e7e5fdc98/jajim.pdfIn PDF document text
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/ag57tocqnhlqj1ivdftfq77fvh/padopub.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607b75fdaba3d---78511431104.pdfIn PDF document text
    • https://ensasoft.com.tr/wp-content/plugins/super-forms/uploads/php/files/dbmdumd88u6tanag0kk1l6k289/renutukeditaniga.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098bb1104e26---tonarapip.pdfIn PDF document text
    • http://citysuji.com/ckfinder/userfiles/files/zezisiluwumikuvogu.pdfIn PDF document text
    • http://amandatravel.com/userfiles/file/ruxoda.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083acf9e6134---92608107056.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/2a747a1e971675f411bbaa4a6400e97b/45993491661.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a91d5dd529a---75763110875.pdfIn PDF document text
    • https://luyenthitoeic.info/userfiles/file/mesagejidugepixikorigu.pdfIn PDF document text
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/78890f46e36ab109fbb25e774fc3da80/debebiw.pdfIn PDF document text
    • https://www.marbelitesa.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609a1235c6b41---44322389216.pdfIn PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/gtmg5e545qavlh278ln0ckik6k/setivanono.pdfIn PDF document text
    • https://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/ahrs53lek479qcr8vcg6urlq1n/lolaxifinapewibixowubu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=always+having+to+clear+my+throatPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e052.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE052 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f863.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF863 16660 bytes
SHA-256: 5bac1e1c1ba23cf3dcc17d3e402cc8386fd4225b69102284014e987a8355d5e8
font_02_sfnt_off00011004.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11004 16056 bytes
SHA-256: 927903e2a9199d45a97ea15152b50a3388c2ef7967bfb807fb0e919b8cbfc046
font_03_sfnt_off00013964.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13964 10924 bytes
SHA-256: 8aca0f196f64925148f59ba2093da4e2b44eebfbc4646b669d28a4d42d833ccb