Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b4839f404a6ce4f…

MALICIOUS

PDF

80.0 KB Created: 2021-09-20 03:47:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 74b05d896e04b23b101a635f4ed89569 SHA-1: 4567daea8139b32d5b8e5b3b6fb315f4cc3e1899 SHA-256: 8b4839f404a6ce4f62afa996f419fd5d8f2a7309ccfb34517122a25cc3eda5fc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file is identified as malicious by ML classifiers and ClamAV, with multiple heuristics indicating it functions as a link farm pointing to potentially compromised websites. The URLs extracted, such as 'https://inwebjor.ru/uplcv?utm_term=harry+potter+ebook+free', suggest a lure for free content, likely to distribute malware or phish for credentials. No scripts were extracted, but the PDF structure and embedded URLs strongly indicate a phishing or malware delivery attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://inwebjor.ru/uplcv?utm_term=harry+potter+ebook+free PDF link annotation
    • http://rcot.by/pics/files/10318799617.pdfIn PDF document text
    • https://dailyiat.com/html_upload/file/zuguvibozujinunedulivopu.pdfIn PDF document text
    • http://immobilieninvestors.de/userfiles/file/vawepedolixadazixes.pdfIn PDF document text
    • https://postele-z-masivu.sk/ckfinder/userfiles/files/totedowidizonemuj.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16147611d79a19---mebotutoxo.pdfIn PDF document text
    • https://brawlcall.com/ckfinder/userfiles/files/tejos.pdfIn PDF document text
    • https://dla-pracownika.pl/pliki_user/File/73072329908.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/161438509d82c9---juvowaleweb.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a6a5409d2a---6300108030.pdfIn PDF document text
    • http://2m-m.eu/userfiles/files/38824708152.pdfIn PDF document text
    • https://tyko.pl/userfiles/file/92900492509.pdfIn PDF document text
    • http://e-motyle.natura2000.pl/imgturysta/files/sototurajotugemifeg.pdfIn PDF document text
    • http://xn--80aadq3ae7aa5k.xn--p1ai/upload/file/55157082533.pdfIn PDF document text
    • http://cameragiaminh.com/upload/files/11083559150.pdfIn PDF document text
    • http://sva-jeanroze.com/xmedia/file/pejelanoz.pdfIn PDF document text
    • http://www.sindafaz.com.br/admin/editor/ckfinder/userfiles/files/34343361635.pdfIn PDF document text
    • https://rtvpuls.com/ckfinder/userfiles/files/nenetudaloputitu.pdfIn PDF document text
    • https://www.hasmow.com.au/application/third_party/ckfinder/userfiles/files/gewejakuzukop.pdfIn PDF document text
    • https://vietnam-pump.com/userfiles/file/zinaj.pdfIn PDF document text
    • http://bubb.cn/up_file/file/riliposipuwimarex.pdfIn PDF document text
    • http://czechnews.cz/userfiles/files/21668159500.pdfIn PDF document text
    • http://mtkshop.com/images/uploads/file/55462721496.pdfIn PDF document text
    • https://mobspace.xyz/web/img/podborky/files/goguzomanufepoxiz.pdfIn PDF document text
    • http://balbu.eu/uploads/news/file/dorasowomesowavofu.pdfIn PDF document text
    • https://ladangmimpi.com/contents/files/vefukizezijogina.pdfIn PDF document text
    • 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_off0000d76d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD76D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF7F 17092 bytes
SHA-256: 93f67cae98d378c61075b1c020d8987776fdb0962f7aa5a0eaa5f4553c564cf0
font_02_sfnt_off00011b54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B54 10276 bytes
SHA-256: 703305b8fc2bfc82b1fd72dbc030ff408497157061c803f287c31c02099f10ab