Malicious PDF — malware analysis report

Static analysis result for SHA-256 957bc7a7c79db0af…

MALICIOUS

PDF

89.7 KB Created: 2021-08-01 00:15:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: af3e334f3e1841169ce9cf7691391237 SHA-1: fdcbeddd26bbd1e73c9113edd8f00bed039798c7 SHA-256: 957bc7a7c79db0af0ed50ed4808695b764a2b49ab36de476d997019b48b5fb2d
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged by multiple heuristics as malicious, including a high-severity PDF_RANDOM_URL_LINK and ML_NYX_PDF_MALICIOUS. It contains a large number of external links, many pointing to compromised websites or disposable domains, indicating a likely phishing or spam campaign. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, but the presence of numerous external links suggests an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://garglob.ru/uplcv?utm_term=how+to+identify+volvo+penta+outdrive
    • http://www.vljainandco.com/userfiles/files/54570048308.pdf
    • https://medicinasolidale.org/wp-content/plugins/super-forms/uploads/php/files/cbd4c8cf89c53b19d0dba4164e5d0057/wemawemazofisewisewujem.pdf
    • https://vresponse.net/userfiles/file/24359827264.pdf
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/acd267ce48b3443fd5a563b7ac577810/5189299217.pdf
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/16085e41fe0bce---47968137678.pdf
    • http://davis-wilford.com/clients/5/5d/5d1655677b271656441dfc21bb295863/File/kuliw.pdf
    • http://gistfamilyreunion.com/clients/8/8c/8cbf0a40baaab9dd4734ff2cdbb1e120/File/84573058084.pdf
    • http://andlupa.com/userfiles/file/77724939033.pdf
    • http://cukrarnakolbaba.eu/obrazky/files/79797944904.pdf
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b02afa71d31---vafikekam.pdf
    • https://www.albispanaderia.com/wp-content/plugins/super-forms/uploads/php/files/9cf6898dfe3074e2a1b9d64746ea0566/74825931742.pdf
    • http://pericosrentcar.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160878c9ed1a6f---94893720789.pdf
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c8d0bf3dfd6---jakemarikamejeposesanaf.pdf
    • https://masihpt1.com/contents//files/15908967095.pdf
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/437dd4628510f57f21e2923aaedbf2c7/gojujipusalavurazajedutik.pdf
    • http://cjatkinson.com/userimages/fowuvijixepigova.pdf
    • http://ambulatorioveterinarioilghirlandaio.it/userfiles/files/xebegat.pdf
    • http://alexlunacoach.com/img/editor/file/mixaboxinobemuza.pdf
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/c0cf3bbb7ef9587d2aab46ec1fb1f3a0/4075846343.pdf
    • http://sport-way.ru/img/file/jalop.pdf
    • http://www.hangmandigital.com/files/file/zawad.pdf
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/5fbeda8c4f1749e06fdb022f2ada4c45/kemalikuluwapefirilalepu.pdf
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1606fe3acc58de---lixigutipiginew.pdf
    • http://polyacer-ecp.com/userfiles/files/20210621_085047.pdf
    • http://chukgoobok.com/files/fckeditor/file/74814568017.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_off0000f81e.bin
4c12a4a90912dab7a93b1cde2c3fa22071dc2d04a107b78e6b3721b3827c3071
pdf-font-stream PDF embedded font (sfnt) at offset 0xF81E 10680 bytes
font_01_sfnt_off000110ba.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x110BA 16792 bytes
font_02_sfnt_off000128cc.bin
773bc6d8bf454181831da6872fb1272433f616a3df795a1f3c9c1ebb7ebfc4a3
pdf-font-stream PDF embedded font (sfnt) at offset 0x128CC 17408 bytes