Malicious PDF — malware analysis report

Static analysis result for SHA-256 31bcd241939d4f3b…

MALICIOUS

PDF

92.5 KB Created: 2021-07-16 11:54:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 7fe8f871591bbf05b0e462d833dd723a SHA-1: 68e561b9362be5dc61bdd8d34f71e76d372d24f4 SHA-256: 31bcd241939d4f3bc19b6120471b806f49ed55ef492de81ab785d6e6bb636110
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to compromised WordPress sites, indicating a link farm designed to redirect users to malicious content. The PDF structure and embedded URLs suggest an attempt to exploit users by directing them to potentially harmful external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/5q2hfcbpr1f6nsese8sesvbrls/jarogasekaxovoterusum.pdf In PDF document text
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/tmp/potefus.pdfIn PDF document text
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/aa7f73f097e96b65f27f3db3fdb16b64/68028981319.pdfIn PDF document text
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/c8a4ae94cdf97c032aac8bf417ff1bca/15151320408.pdfIn PDF document text
    • https://christembassybarking.org/wp-content/plugins/super-forms/uploads/php/files/3ee265060b86aeea2a2b9a0a62c06d73/dizojosasejuduj.pdfIn PDF document text
    • http://hbleg.com/admin/userfiles/files/14353748816.pdfIn PDF document text
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/n72uefpbfh5m7ts7ad486ttm3s/71849950152.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b3022eff6f---jugetuvokomeb.pdfIn PDF document text
    • https://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/f2854a61a2c74e506bd796e6d42e880d/61714968096.pdfIn PDF document text
    • http://chukgoobok.com/files/fckeditor/file/82520841093.pdfIn PDF document text
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160ba2703850fa---6596860446.pdfIn PDF document text
    • https://sgdivorcelawyers.com/wp-content/plugins/super-forms/uploads/php/files/bc60540c3a90bd471c9a16b99f151a02/pekimafixerupebujuda.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ee583b90c74---81277299322.pdfIn PDF document text
    • https://dintek.eu/uploads/file/mufej.pdfIn PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b79d2258c0---52424042135.pdfIn PDF document text
    • http://on-video.com/movies/movie_data/file/xejumibimubiwefonuzaloz.pdfIn PDF document text
    • http://findmealocalpainter.com/insurazon/admin/userfiles/file/bazinux.pdfIn PDF document text
    • https://eventaipei.com/upload/files/vapataz.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/75340306929.pdfIn PDF document text
    • http://aklond.com/UploadFilesfile///2021050206304896.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/b71ef6c59e91693070499073e8773242/27158003974.pdfIn PDF document text
    • http://art-lan.ru/uploads/assets/file/pekexi.pdfIn PDF document text
    • https://www.infrascale.com/wp-content/plugins/super-forms/uploads/php/files/a797136415004981bd68192dcfdf164e/44459779095.pdfIn PDF document text
    • https://serini-cloud.pl/uploads/editor/file/famuravovo.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079ba42ef415---jerakeriraxirabuf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=toy+story+andy+comingPDF 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_off000107ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107AD 10612 bytes
SHA-256: faf518838cdc007620f5f65341bd49a4780109be16e7bd5f041165afcfb9fe74
font_01_sfnt_off00011fbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FBF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000137d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137D1 17216 bytes
SHA-256: f6411bc5e3cbe45bf125cced60cd96310c70b76ba16ade30eacf26ff3cd4d426