Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4f8fa50bf21e245…

MALICIOUS

PDF

87.0 KB Created: 2021-09-05 03:53:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4fdc7006be13bfaa6ec30be739645387 SHA-1: e6588b32b7a392ab3908c8fc095cec7b193f2f87 SHA-256: c4f8fa50bf21e245b6ede1feb2d5bcdad97afe9fbb4fa9d946240ca6b577d144
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://good163.cn/Uploadfiles/files/niboxunomoluzevew.pdf In PDF document text
    • http://www.lugashotel.com/data/editorfile/23909911305.pdfIn PDF document text
    • http://easternhoteljeju.com/FileData/ckfinder/files/20210620_DA992BEBD1275288.pdfIn PDF document text
    • http://skomi.ru/img/files/file/vufesomu.pdfIn PDF document text
    • http://ultraljud.nu/bild/files/80037815844.pdfIn PDF document text
    • https://catherinehourihan.art/wp-content/plugins/super-forms/uploads/php/files/bfc797ed6303ea4e26b6e513759c392e/vezulezetog.pdfIn PDF document text
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/0559faf002b8594c7905043dce1342cc/62817281783.pdfIn PDF document text
    • http://cropscipublisher.com/files/upfiles/file/numidolapukezili.pdfIn PDF document text
    • https://catherinehourihan.art/wp-content/plugins/super-forms/uploads/php/files/e22d37c5643e9214c460c4242740ce31/15746893688.pdfIn PDF document text
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/13bcde7fdd4635333619c4c339598074/pudiduva.pdfIn PDF document text
    • http://vasvaripalmuzeum.hu/upload/file/pumotimomepexirise.pdfIn PDF document text
    • http://witnesstherealist.com/wp-content/plugins/super-forms/uploads/php/files/38a3888c7c26949621c434b7f4f7b173/kaxenerozefeluniwu.pdfIn PDF document text
    • http://heldermusic.nl/ckfinder/userfiles/files/rizijujuzugagarukikej.pdfIn PDF document text
    • http://findmealocalpainter.com/insurazon/admin/userfiles/file/44020304636.pdfIn PDF document text
    • http://chnli.tw/CKEdit/upload/files/23946958138.pdfIn PDF document text
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607849d1416bd---pezekiredojiba.pdfIn PDF document text
    • https://regenerativetherapyforpain.com/wp-content/plugins/super-forms/uploads/php/files/6d95b397d9c7992e64ba4a42776eea0f/88357495811.pdfIn PDF document text
    • https://edoxmarketing.com/wp-content/plugins/super-forms/uploads/php/files/u6vk47cle375lre0hvb14ae9u7/9919897506.pdfIn PDF document text
    • http://www.ssc-ras.ru/ckfinder/userfiles/files/54933917709.pdfIn PDF document text
    • https://airxps.com/userfiles/files/89912757262.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/22982944361.pdfIn PDF document text
    • https://svarovanijelinek.cz/ckfinder/userfiles/files/wamigamim.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/uchl3kf4jqijsb7nlgm2ta5g65/jegebefud.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=calculating+average+speed+and+velocity+worksheetPDF 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_off0000eb40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB40 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010352.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10352 18724 bytes
SHA-256: ffcb84b4094064c08009b84a59c7294ae31961aeb36a3007c944585bcb17839d
font_02_sfnt_off00013372.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13372 11284 bytes
SHA-256: 60115c290a43191862b50ae65fb43bb8a61d3b44a17bdf85805188e6d636e906