Malicious PDF — malware analysis report

Static analysis result for SHA-256 83487b1dc31df14a…

MALICIOUS

PDF

83.3 KB Created: 2021-09-09 14:04:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1ae2d69eefd56f16a80a828f3970e7cc SHA-1: 0059dd8373b8d75c56eb7da6fa1b1e198a662a8c SHA-256: 83487b1dc31df14a2e45bd542b14ec77cc832e0d57da7645b73c883a5cdb5539
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan threat. It contains a link farm with numerous URLs, many hosted on compromised CMS upload directories or disposable domains, suggesting an attempt to redirect users to malicious sites. The presence of embedded URLs and the overall structure point towards a phishing campaign, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://cructi.ru/uplcv?utm_term=harry+potter+4k+download
    • http://fuyu.010bi.com/ckfinder/userfiles/files/vasizevizafiselazosasigu.pdf
    • https://unitjaya.com/contents/files/44793923869.pdf
    • http://cukrarska-vyroba.cz/UserFiles/File/womisuwik.pdf
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/811b7df00792ef716181b6dac30abdf8/97433340065.pdf
    • https://classoft.ro/userfiles/file/35023731612.pdf
    • http://infas.cz/images/wiswig/file/61201412709.pdf
    • https://rcvizovice.cz/ckfinder/userfiles/files/20575876062.pdf
    • https://anhhuynoithat.com/asset/files/84926801560.pdf
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/161384e5db52e1---torigo.pdf
    • http://reichspfarrer.sk/file/3698008403.pdf
    • http://neodentpetrosino.it/userfiles/files/rebamerujoxomokerepok.pdf
    • http://shop-exclusive.cz/userfiles/file/vazukuselotalejulenev.pdf
    • http://topup-fight.com/ckfinder/userfiles/files/30657008799.pdf
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16133ca761e463---mavonejipedaxejidoge.pdf
    • http://pspectr.ru/userfiles/file/85379986014.pdf
    • http://scandinavia-ex.com/images/blog/file/71029709559.pdf
    • https://rainbowfurnitures.com/files/files/zituxukinitumuxefadenuda.pdf
    • http://anpharma.net/upload/files/95695659625.pdf
    • https://goez3.com/10005001208290177/ckfinder/userfiles/files/34172333358.pdf
    • http://plusdesignwebsite.com/userfiles/file/lilenotujolu.pdf
    • http://internet-trade.eu/UserFiles/file/40289138730.pdf
    • http://bielwod.com/userfiles/file/wolijuvopoguxupaf.pdf
    • https://eetravel.net/file/1650777390.pdf
    • http://land89.com/ckupload/files/98186121754.pdf
    • http://kargiskola.ge/myadmin/ckeditor/ckfinder/userfiles/files/linavijeraxobu.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e2f6.bin
4259536fc13f7709ded932ed959c088e285913f3e835eae02dc6ca7659ffa916
pdf-font-stream PDF embedded font (sfnt) at offset 0xE2F6 17248 bytes
font_01_sfnt_off00010f69.bin
774eff793cdf28d3e65537646a9174827e54b171ac63a09aee76856de5195f85
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F69 10488 bytes
font_02_sfnt_off00012770.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12770 16792 bytes