Malicious PDF — malware analysis report

Static analysis result for SHA-256 87a8f2cfa6b0af08…

MALICIOUS

PDF

88.7 KB Created: 2021-09-05 09:31:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 4ffbc46b5a67c382ad0891e57b5a4b79 SHA-1: e170a51b8ccd80d08d907ab35c70b881c0d08cba SHA-256: 87a8f2cfa6b0af08984334fdb1ab03cadc3bbf891aa28a1efe11ed2343fb45a4
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified the document as a link farm pointing to multiple compromised WordPress upload directories, suggesting an attempt to host malicious content or phishing pages. The presence of numerous unknown URLs supports this finding.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606e2105a6b6a---rofojoki.pdf In PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1fbd705099---69236091959.pdfIn PDF document text
    • http://www.rkcomdesignservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ce737ee22c---tugexiboj.pdfIn PDF document text
    • http://www.rosabrockenhaus.ch/ckfinder/userfiles/files/71827441797.pdfIn PDF document text
    • http://psychologkmalinowska.pl/ckfinder/userfiles/files/99236175690.pdfIn PDF document text
    • https://studiorampinelli.com/file/gurulizelutasutu.pdfIn PDF document text
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/sinuvimifeluvuvevawolozut.pdfIn PDF document text
    • http://spoilersmensgolfclub.com/clients/865201/File/60748439086.pdfIn PDF document text
    • http://www.neoneofitou.com/ckfinder/userfiles/files/mitikutexinepezosiperu.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c9598cb6cfd---xinukosuni.pdfIn PDF document text
    • http://tofuyatogo.com/uploads/files/liwebuzipodizene.pdfIn PDF document text
    • http://ibtaker.ps/userfiles/file/59946868532.pdfIn PDF document text
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/160780d5f02451---wokakev.pdfIn PDF document text
    • https://club-sports.net/uploads/products/files/zumajabanovositafepu.pdfIn PDF document text
    • https://voyageaventurenepal.com/upload/files/raguf.pdfIn PDF document text
    • http://autosklo.sk/pictures/file/9630143164.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/531006e4158955a97335df2f9078a495/jurefileraxekifi.pdfIn PDF document text
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfe470d413c---nolabikudib.pdfIn PDF document text
    • https://eminencesolutions.in/resources/userfiles/file/82999390149.pdfIn PDF document text
    • https://www.oasipizza.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c92439dbd96---sezodifugipavopanuzepukul.pdfIn PDF document text
    • http://b-solutions.net/userfiles/file/35857068949.pdfIn PDF document text
    • http://studiocariola.com/userfiles/files/winowepepegup.pdfIn PDF document text
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/160d749b49c305---505165274.pdfIn PDF document text
    • http://karpatskiles.ru/store/files/52258537878.pdfIn PDF document text
    • http://lindendirect.com/tempimg/file/33897881505.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=pediatric+sepsis+and+septic+shock+pdfPDF 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_off0000f4ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4EA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010d01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D01 10764 bytes
SHA-256: 59ce9e46fa3904aa80ddae7cd645bb3cd64b7bd927c8ed86d1f69920feddbf22
font_02_sfnt_off000125b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125B3 18264 bytes
SHA-256: 828bbd0f4b90c7f024de656301e27a53e5c40a92fab2a5d3152f7a0f9c4e3249