Malicious PDF — malware analysis report

Static analysis result for SHA-256 c91ce2037e1968b2…

MALICIOUS

PDF

81.5 KB Created: 2021-09-22 13:51:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 81842ce536d2e8980d942ff4b62a6d04 SHA-1: 1afd33d46a6ec126ce21c8653a3746d7721c923f SHA-256: c91ce2037e1968b233b5ce59348e54c5eccd513a89d819f155959eb80f6aff54
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It contains numerous embedded URLs that point to compromised WordPress sites and other disposable hosting, indicating a link farm designed to redirect users to malicious content. The presence of these links suggests an attempt to lure victims to external sites for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://ketchas.ru/uplcv?utm_term=avatar+the+last+airbender+ppsspp PDF link annotation
    • https://tivirtual.com/userfiles/file/77985875939.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/b8ouuskko5bpi6ocavc8b9c51p/63137645740.pdfIn PDF document text
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613900dc943a9---gudozejupisukomosi.pdfIn PDF document text
    • https://censcakmu.org/board/file/files/zukejifomewonerev.pdfIn PDF document text
    • https://el-tall.pl/pics/file/97049443243.pdfIn PDF document text
    • https://encoyun.com/calisma2/files/uploads/xisexefibe.pdfIn PDF document text
    • http://rotarytattoomachine.co/project-new/christianbook/upload_images/file/44933383732.pdfIn PDF document text
    • https://brs.jo/userfiles/files/wexobege.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613b2975c2474---46687077256.pdfIn PDF document text
    • https://heritagecambodiatravel.com/userfiles/file/2465867383.pdfIn PDF document text
    • http://bluebirdcanada.com/FileData/ckfinder/files/20210911_0E593FCFBA88DDE7.pdfIn PDF document text
    • http://cmtl.in/uploads/userfiles/file/file/54869757870.pdfIn PDF document text
    • https://bloomeng.com/uploads/22763079923.pdfIn PDF document text
    • http://kkagro.com/media/images/upload/file/78997726701.pdfIn PDF document text
    • https://bunianco.com/other_files/File/67464169936.pdfIn PDF document text
    • https://skyzoan.com/cake/beta/userfiles/file/59575459314.pdfIn PDF document text
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/51da80fd5e6b6121e0a34a4be3914a23/jilugobimelavorilutik.pdfIn PDF document text
    • https://kalyna.ua/sites/default/files/userfiles/file/pajomejezivomugidabuna.pdfIn PDF document text
    • https://beldapromosyon.com/calisma2/files/uploads/33690145702.pdfIn PDF document text
    • https://pointswestliving.com/ckfinder/userfiles/files/6102089796.pdfIn PDF document text
    • https://www.ftha.org/admin/ckfinder/userfiles/files/12332387467.pdfIn PDF document text
    • https://balarampurblock.in/ckfinder/userfiles/files/24764944916.pdfIn PDF document text
    • https://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/fkguqejvg8ihmcjn3uj1uu7qq2/jumezabebifujonuwa.pdfIn 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_off0000d915.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD915 18020 bytes
SHA-256: 987932823687d7e2b942dfe04105426e9c8b1b3a7d439a69cd8b7603fde441bf
font_01_sfnt_off00010835.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10835 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001204c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1204C 10556 bytes
SHA-256: ac7caca5c4d64a94f1eff5afc77d430517440eecb2c3292a9bb8e5cd4970e70d