Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb6d97e3b682aa7c…

MALICIOUS

PDF

83.7 KB Created: 2021-09-05 07:56:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 1054bc9dba707a8ef4b26a29d9ef0382 SHA-1: 2e0a07d576185979c3b6873c0417a96f8e8194cd SHA-256: cb6d97e3b682aa7cc90f192a21aafa15099a47932759ac2cd730588fb8e90b06
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to websites hosted on compromised CMS uploads and disposable domains, identified by heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier and ClamAV also flagged this file as malicious, indicating a high likelihood of phishing or malware distribution. No scripts were extracted, but the link farm structure itself is the primary attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://thessalonikiflights.com/files/files/rezodewab.pdf In PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160e551408cd18---nevelipopive.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/16109c4d936ca2---93458306966.pdfIn PDF document text
    • http://adabaskimerkezi.com/upload/file/55992076514.pdfIn PDF document text
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/aa81c575b606b9077071a3ab61f805fd/jixefejegutimugigilolu.pdfIn PDF document text
    • http://www.gulbaharsigorta.com/contentData/file/57376816854.pdfIn PDF document text
    • https://5of7edwardstreet.com/assets/media/files/31493557761.pdfIn PDF document text
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b76d82cceda---26467151714.pdfIn PDF document text
    • http://farmaciafasolis.eu/userfiles/files/dazak.pdfIn PDF document text
    • https://dewalt-naradi.cz/media/upload/editor/file/14448658339.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f0c988b69d---dorowimoki.pdfIn PDF document text
    • https://polskieplytki.com/wp-content/plugins/super-forms/uploads/php/files/266947c66ff6e6b3a4d7665b835edef9/6946974127.pdfIn PDF document text
    • http://ecosdaliberdade.com/ckfinder/userfiles/files/5840561153.pdfIn PDF document text
    • https://s-serviss.lv/userfiles/file/68665705500.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/78906014300.pdfIn PDF document text
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/8a039c92acb20d6b9c881a957d8e966f/48901318451.pdfIn PDF document text
    • http://dienlanhlongan.com/upload/files/14424558414.pdfIn PDF document text
    • https://thietbigas.net/media/files/pevemuwabatu.pdfIn PDF document text
    • http://ourconn.com/userfiles/file/202108210301464843.pdfIn PDF document text
    • http://mosjob.ru/images/file/7353707136.pdfIn PDF document text
    • https://bouwservicewinthagen.nl/userfiles/image/file/99948487022.pdfIn PDF document text
    • http://irollee.com/userfiles/file/tezipo.pdfIn PDF document text
    • http://inlygiaylynhua.com/upload/files/navulepuvosekisojojerev.pdfIn PDF document text
    • http://hitecds.com/userfiles/file/81140076707.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=ias38+intangible+assets+pdfPDF 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_off0000e0d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0D5 10924 bytes
SHA-256: b56aa6c5dfc31bfe0601cde18f437c0a48f1cab7f2310eebafaaa8ed0f71d367
font_01_sfnt_off0000f9d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9D5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000111e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111E7 17932 bytes
SHA-256: 4eb4a0b79cb854b2b2dd209f6872d09ccdf2099afc7274143a13cbd398f0ec95