Malicious PDF — malware analysis report

Static analysis result for SHA-256 87c3715e34bb58cf…

MALICIOUS

PDF

82.8 KB Created: 2021-09-12 07:32:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 0f5ffe2c9562194d87116e8b01578f44 SHA-1: 3f72bad410e93a62b069460e73125b863acd6e1c SHA-256: 87c3715e34bb58cf4940505b0a66ec353518e2667d9242920a251f82b514af40
156 Risk Score

Malware Insights

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

The file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Static analysis revealed it functions as a link farm, containing numerous URLs pointing to various domains, some of which are hosted on compromised CMS upload directories or disposable domains. This pattern suggests an attempt to lure users to malicious sites for phishing or malware delivery.

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://currenwatch.myhost360.cn/file/upload/files/09-05-03-23-09-72.pdf In PDF document text
    • http://csc0516.com/userfiles/file/20210902145838_49pfz1.pdfIn PDF document text
    • https://ateliersmq.com/pevron/www/img/file/84385554412.pdfIn PDF document text
    • https://afgventuregroup.com/cfiles/file/9225005936.pdfIn PDF document text
    • https://goez3.com/10005001208290177/ckfinder/userfiles/files/22443677928.pdfIn PDF document text
    • http://lixupeng.com/uploads/files/27936125012.pdfIn PDF document text
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ed429ce24f---55164119233.pdfIn PDF document text
    • http://musicpark-live.de/userfiles/file/zoxetozakujuzawonavotek.pdfIn PDF document text
    • http://materialdeestudo.top/userfiles/files/99108599127.pdfIn PDF document text
    • https://nawaasha.org/userfiles/file/7520128491.pdfIn PDF document text
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/3d89e83b039b1a6fa55ac4f8bf4651da/notekirivumukobikazora.pdfIn PDF document text
    • http://sns-russia.ru/userfiles/file/duwutusek.pdfIn PDF document text
    • http://trungtamsangloc.vn/uploads/ck_upload/files/86635676880.pdfIn PDF document text
    • https://www.pessin-location.fr/ckfinder/userfiles/files/98382745961.pdfIn PDF document text
    • http://chinajnbt.com/images/upload/File/badetu.pdfIn PDF document text
    • http://thepnguyentran.vn/media/ftp/file/kuvokawexiv.pdfIn PDF document text
    • http://templeton.sk/userfiles/file/zufuwikabugekugov.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/mboafvr1ran7mlnu9fhouf2pp3/bibizuvaj.pdfIn PDF document text
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/pt9sekrat2gsamak4126utvkl6/vabawed.pdfIn PDF document text
    • http://studiolorenzino.eu/userfiles/files/71109577511.pdfIn PDF document text
    • https://bamfieldrental.com/userfiles/file/boxopuloxu.pdfIn PDF document text
    • https://metrosecuritynepal.com/assets/userfiles/files/83390190859.pdfIn PDF document text
    • https://sarenpinler.com/calisma2/files/uploads/selelazapegitebelatojed.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=vidmate+apps+download+2019PDF 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_off0000de9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE9B 10968 bytes
SHA-256: 4e758a1ac666d01541a6941e2c525840825a06661aaa79df9ccd88c09218918e
font_01_sfnt_off0000f826.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF826 17516 bytes
SHA-256: 42706e99276251c3cf9c13710ee8dd5ed55aa4e7911ed7279c4c04efcd540e74
font_02_sfnt_off00012542.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12542 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1