Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b1a1f0d5fed7ea0…

MALICIOUS

PDF

104.9 KB Created: 2021-08-13 14:13:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 51ba8f3e9b8723a4c9e5124d5fdb8330 SHA-1: 162843e1a51668d68653a5696350bb0d50281ec1 SHA-256: 7b1a1f0d5fed7ea0d0506d4fee9a7377316047a066be64ff03fe52fc4b7e3647
156 Risk Score

Malware Insights

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

The PDF contains a link farm directing users to multiple URLs, many of which are hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The document body is heavily obfuscated and does not provide direct clues, but the heuristic firings point to a malicious link farm designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9918

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://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bebfdea544a---tetikoden.pdf In PDF document text
    • https://fertilizergranulatorprice.com/d/files/tedutukik.pdfIn PDF document text
    • https://www.unicodesystems.com/wp-content/plugins/super-forms/uploads/php/files/stlqf0ngcchdln8qma9b7mug24/xulinazapovatogibozogole.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/xasovewijexowajera.pdfIn PDF document text
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/ic0sj5u89ue2qi0glccih3giu9/pevonoluxazujofuxikozafe.pdfIn PDF document text
    • https://yarpaket.ru/userfiles/file/woboropuzakosutefa.pdfIn PDF document text
    • https://altonika.pro/files/fck/file/pokodolixunevizi.pdfIn PDF document text
    • http://gursakaryahukuk.com/images/file/17748555665.pdfIn PDF document text
    • https://sancarspune.com/wp-content/plugins/super-forms/uploads/php/files/6c8d5ac3b94e80436d25be1f10954a55/1107739128.pdfIn PDF document text
    • http://ascensionchina.com/userfiles/file/tunewumeropub.pdfIn PDF document text
    • https://www.emma-solutions.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609774e8dd6e3---rodafewaxosabuno.pdfIn PDF document text
    • https://sanxuattrucauthangkinh.com/Images_upload/files/zefofunekasiguvoru.pdfIn PDF document text
    • https://www.marvistasales.com/wp-content/plugins/super-forms/uploads/php/files/c8a8d2c595cad8c112b4fd7a478fa53f/minumupatutibigoreti.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/v77o1t957ak4ds3t82ada20i10/ralosafonevewotosibuwufun.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a5bc13130a7---xebawo.pdfIn PDF document text
    • https://dixietemporarystorage.com/wp-content/plugins/super-forms/uploads/php/files/fd5f594fdbb572ce7e05307144db78c5/dubabodi.pdfIn PDF document text
    • http://landpas.pl/upload/file/41006183889.pdfIn PDF document text
    • http://mousike.it/img_ins/files/zexukesapefimubejaniv.pdfIn PDF document text
    • https://mmagame.com/userfiles/file/97436007192.pdfIn PDF document text
    • http://vitalenzyme.com/uploads/fckupload/file/20573781263.pdfIn PDF document text
    • http://copelandreunionla.com/clients/6/66/66f6f3de7053633686652f51c4c00696/File/nakavurajovovoferen.pdfIn PDF document text
    • http://gymostrov.org/gymostrov/userfiles/file/zukirovopefi.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7c7093ceee---javufupilizonofutuz.pdfIn PDF document text
    • http://phuclocvienjsc.com/uploads/image/files/tenatuvojazuluji.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/160a5bcfa5168b---41404053070.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/72752e99390ccfcaea3933554c1e57a2/86112362323.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c6d3d9e6323---62783000032.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=human+anatomy+%26+physiology+laboratory+manual+cat+version+pdfPDF link annotation
    • https://medlineplus.gov/anatomy.htmlIn 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_off00013abf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13ABF 9936 bytes
SHA-256: 7250bc5814e105cdc5848dff78740d69f61a170f7c67225489ae00acad9dc716
font_01_sfnt_off000150ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x150AB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000168bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x168BD 17168 bytes
SHA-256: df2fd8df16014e66538a0ce4c88cdcfa4ef88724856a516de95730997be3b3c7