Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cd5aa0fa69f4a0b…

MALICIOUS

PDF

82.9 KB Created: 2021-09-05 16:47:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 6fdd7c60df7af561bdddf5866200d787 SHA-1: ac5483a758b8e7296952ed18ab3bb76b0a5a28c8 SHA-256: 4cd5aa0fa69f4a0b9a2217be208eba6e7950b003340a87c42a20379e1b64e442
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code or redirecting users. The presence of numerous links, many pointing to compromised WordPress sites and disposable hosting, suggests a link farm designed to obscure the ultimate destination or host phishing content. ClamAV detection and ML classification further support its malicious nature, likely as a phishing or trojan delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://synerhu.ru/uplcv?utm_term=vistas+ortogonais+pdf PDF link annotation
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a109935514e---lawumumowogutijapipas.pdfIn PDF document text
    • https://forumhotel.by/wp-content/plugins/super-forms/uploads/php/files/pg2r9g6i1mq6orij5rg1bkcb85/kuduxatusi.pdfIn PDF document text
    • http://skiflogistics.ru/userfiles/file/50306836198.pdfIn PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a48fafa10c7---59276770090.pdfIn PDF document text
    • http://szjglaw.com/uploadfile/file/2021072417022773499.pdfIn PDF document text
    • https://cpc-serbia.org/js//files/78426569732.pdfIn PDF document text
    • https://locktactyuma.com/ckfinder/userfiles/files/45039481344.pdfIn PDF document text
    • http://szerecsen.hu/editor_up/97482505840.pdfIn PDF document text
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/trsvrqiaeg1g23aea9k6mgfh14/8359773292.pdfIn PDF document text
    • https://regenerativetherapyforpain.com/wp-content/plugins/super-forms/uploads/php/files/aef20d2686bba7b0889cbdbdbd9ed7a3/56536533524.pdfIn PDF document text
    • http://mientaytourist.com/uploads/files/wexerigefuroxabafixaga.pdfIn PDF document text
    • http://holidayservicemarsala.it/userfiles/files/zeguzugapareva.pdfIn PDF document text
    • http://englishkan.net/UserFiles/File/ruburitumazadusubo.pdfIn PDF document text
    • http://dirabrealtors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc4700c0fee---xotezagajawawitotaposuw.pdfIn PDF document text
    • http://etoprosto.ru/ckfinder/userfiles/files/texixadesuwo.pdfIn PDF document text
    • http://longarmquiltacademy.net/fckeditor/userfiles/file/ronodi.pdfIn PDF document text
    • https://ipcare.nl/wp-content/plugins/super-forms/uploads/php/files/uv907ui4pg9h7q223n650q08fb/46482614683.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/160781536011cb---27756088955.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/sdasi9gkflp5nhov00davn21d2/fokujididonajexuw.pdfIn PDF document text
    • http://sistarelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/18319045791.pdfIn PDF document text
    • https://podimercrm.com/img/files/vetavaronirifelumidawada.pdfIn PDF document text
    • http://markfarolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/bafizuxumesotik.pdfIn PDF document text
    • https://www.kalirich.com/wp-content/plugins/super-forms/uploads/php/files/54vkilkv3iq3etpdijtlsmha22/regupumenufarotisak.pdfIn PDF document text
    • http://tecs4.com/intranet/ckfinder/userfiles/files/derobezazufakolikome.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_off0000dac8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAC8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f2da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2DA 19264 bytes
SHA-256: ffeff2e642307515757f3f78fbd2e932866bf64fd94308b8e75ab94523b4572a
font_02_sfnt_off000124a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124A9 10464 bytes
SHA-256: 54e0425e7074d10d82183744173ea9759812c31ddfa5a61895a3a0350cbf414b