Malicious PDF — malware analysis report

Static analysis result for SHA-256 8628f8a408ed3f98…

MALICIOUS

PDF

83.8 KB Created: 2021-09-18 23:53:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 41ca58a73ca6690c2399c44a3431b346 SHA-1: b5eaa6af13cbdf144f970efffc05032a1fc165ed SHA-256: 8628f8a408ed3f985af871a0d7cbcf5e73ccf41d0b5a38049d831d94cb46f3c9
156 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous URLs pointing to various websites, many of which appear to be compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or redirecting users to malicious content. The presence of multiple external URIs and compromised CMS upload links supports the classification as a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 https://f2h63c2.ip4secure.net/upload/files/14362596110.pdf In PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/161411794a1478---82379756484.pdfIn PDF document text
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/lrvhmrmgl6f0vr9jbe2ldlsvv3/1693778977.pdfIn PDF document text
    • http://esipro.lu/userfiles/file/13958074848.pdfIn PDF document text
    • https://rugsdirect4u.com/uploadedfiles/file/bifupo.pdfIn PDF document text
    • https://delcinfo.ru/img/files/files/nixumumezarixudakaxaxa.pdfIn PDF document text
    • http://studiogiamberardino.it/userfiles/files/1035438431.pdfIn PDF document text
    • http://crystaltrade.hu/data/file/56703799327.pdfIn PDF document text
    • https://facades-et-traditions.com/actualites/file/41534973815.pdfIn PDF document text
    • http://szintai.hu/ckfinder/userfiles/files/momikanerotasowumulemava.pdfIn PDF document text
    • https://popcouncilinstitute.org/wp-content/plugins/super-forms/uploads/php/files/4741708fd2f645aa3372793116e98ad0/91090576604.pdfIn PDF document text
    • https://www.hkha.com.hk/ckfinder/userfiles/files/71920055628.pdfIn PDF document text
    • https://nakatarikaszel.pl/app/webroot/userfiles/file/fogopolajajafivezajise.pdfIn PDF document text
    • http://iscelenie.info/files/file/73848436570.pdfIn PDF document text
    • https://pasarantogel.com/contents/files/32013141075.pdfIn PDF document text
    • http://virus-safe-zone.com/ckupload/files/vavanupoxuxipenuj.pdfIn PDF document text
    • https://erdenetpost.mn/userfiles/files/munesinum.pdfIn PDF document text
    • http://utcsp.rustyramone.com/uploads/files/viludurowemepopu.pdfIn PDF document text
    • http://festacreativita.org/userfiles/file/vewurenasisixaretu.pdfIn PDF document text
    • http://abcgsgeds.friendship-match.com/upload/files/5095479051.pdfIn PDF document text
    • http://ecosdaliberdade.com/ckfinder/userfiles/files/luzukezowunudexob.pdfIn PDF document text
    • https://cuichi177.com/uploads/files/202109070402342851.pdfIn PDF document text
    • http://symbioticlifetech.org/attfile/fckimg/file///20210903232610_274231721.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=killer+bean+mobile+gamePDF 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_off0000e14d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE14D 10316 bytes
SHA-256: 0d3b1fb529ceac9204bd1943b77cbe1e61fad0efcbd31930740e4f01368f68f6
font_01_sfnt_off0000f871.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF871 18764 bytes
SHA-256: ea162c12352f54305b8c55f9988ceaf6b47adc91e33c4f83cc1f157c0aa406d9
font_02_sfnt_off00012961.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12961 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1