Malicious PDF — malware analysis report

Static analysis result for SHA-256 72aa3dc131bfc887…

MALICIOUS

PDF

78.5 KB Created: 2021-09-14 23:13:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8eae1f1406efe4702f9f6510c0a2045a SHA-1: 1e5d664c3840d6966c9b44539845fadca3a8e1a3 SHA-256: 72aa3dc131bfc887851fe870809464163dcaaef48bc806df2c5f7928f2ee6919
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a PDF link farm, with multiple URLs pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or SEO manipulation scheme. The presence of numerous embedded URLs, some with UTM parameters, further supports the attack pattern of directing users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://adamant54.ru/userfiles/files/21513163369.pdf
    • http://tvoirostov.ru/ckfinder/userfiles/files/jerepusoxofesorepaterodax.pdf
    • https://femagnet.com/upload/edu/article/file/wavepomaxopedakudilan.pdf
    • http://laptopcuhaiphong.vn/upload/files/75085162807.pdf
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1613ca01b870c3---31947658217.pdf
    • https://www.barrau-philippe-sedeco.fr/ckfinder/userfiles/files/kusanovobi.pdf
    • http://www.cottagegrad.ru/files/file/67376088542.pdf
    • https://www.unicodesystems.com/wp-content/plugins/super-forms/uploads/php/files/kpa2p6da54mrlgkeejtnlilth4/tonapowinazijivo.pdf
    • http://stl-hk.net/userfiles/8203814849.pdf
    • http://ptichile.cl/userfiles/file/mudug.pdf
    • https://healthmatters.me/userfiles/file/vamub.pdf
    • http://www.thunderesp.com/ckfinder/ckfinder.htmlfiles/fokev.pdf
    • http://zaragozalawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gipepopoxewewiralagoj.pdf
    • https://marikakozmetika.hu/editor_up/vimojilulediz.pdf
    • http://mvsexpo.ru/admin/ckfinder/userfiles/files/nikaxefoxusex.pdf
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1612eac0460cc0---98173581939.pdf
    • https://artlabjo.com/userfiles/file/65790285116.pdf
    • http://optometrystaprzemysl.pl/userfiles/file/69391971412.pdf
    • http://ccsup.co.th/uploads/ckfinder/files/niziwesagaxozuxabidewebe.pdf
    • https://alkathirilaw.com/userfiles/files/11701399110.pdf
    • http://iberia-ex.com/images/blog/file/93816214599.pdf
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/tbi9ao9912invuiukjeoclsgot/54611916695.pdf
    • http://chanakyaaerospacedefence.com/userfiles/file/kanuboba.pdf
    • http://npcbalkan.net/ckeditor/ckfinder/userfiles/files/tubogezapos.pdf
    • http://radtel-sport.pl/userfiles/file/pagomenatizebodotibegu.pdf
    • http://studiodispirito.it/userfiles/file/defagobufinazatuma.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=avakin+life+avacoins+mod
    • 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_off0000c6df.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC6DF 16792 bytes
font_01_sfnt_off0000def1.bin
c032362ce8b73f206e1fd10aac01e50df60ddbf9d8f7a1b62f2929d280d10aab
pdf-font-stream PDF embedded font (sfnt) at offset 0xDEF1 20860 bytes
font_02_sfnt_off00011482.bin
14e0039b051743fa74bb6820f148143e2a47dc1c168ac455e814cdb3a8c7f393
pdf-font-stream PDF embedded font (sfnt) at offset 0x11482 10580 bytes