Malicious PDF — malware analysis report

Static analysis result for SHA-256 35bdf61fcbdb45f0…

MALICIOUS

PDF

80.2 KB Created: 2021-09-14 05:51:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 2d3fb89b2190bd40228c1140b01ac82e SHA-1: fea7cb3916e2ff7c41028a49fbb65da50eae6dfc SHA-256: 35bdf61fcbdb45f01737e5f61316fcc834d7e238e1f102c6cd358e3eecdd5ac6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple external URLs, some hosted on compromised WordPress sites. The presence of numerous links, including those with UTM parameters, suggests an attempt to direct users to potentially malicious or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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 https://laborke.ru/uplcv?utm_term=add+fragment+to+activity PDF link annotation
    • https://gimenezricarte-deltabogados.com/ckfinder/userfiles/files/28398350313.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/1b73b5229ad8342b8c990e75297fcc5d/4614787182.pdfIn PDF document text
    • http://babywagen24.de/userfiles/file/68505831319.pdfIn PDF document text
    • http://learnazia.com/fck/imagesfile/15290113066.pdfIn PDF document text
    • http://tuzoltosagmihald.hu/userfiles/file/rozuwuvap.pdfIn PDF document text
    • https://ags-car.60km.com/upload/files/7951979269.pdfIn PDF document text
    • https://strefaokazji.pl/uploaded/file/13921212883.pdfIn PDF document text
    • https://unaizahic.com/Files/files/82201265037.pdfIn PDF document text
    • http://perksys.com/userfiles/file/fuduzovadukipalunozine.pdfIn PDF document text
    • https://salondumariagededijon.com/userfiles/file/85657664994.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/1613f3c3dd7ef7---naforitojiputo.pdfIn PDF document text
    • https://simondaulte.com/ckfinder/userfiles/files/sitiwenirilik.pdfIn PDF document text
    • https://eklyps.net/images/file/65058173473.pdfIn PDF document text
    • http://hvpeds.com/upload/contents/file/59485187584.pdfIn PDF document text
    • http://centronegozi.com/public/nipimekasogorutenumuwusew.pdfIn PDF document text
    • http://iproperty.ae/userfiles/file/lopuvinagika.pdfIn PDF document text
    • http://ufnk.fr/app/webroot/files/file/84892736761.pdfIn PDF document text
    • http://easyliveconstruction.com/ci/userfiles/files/guweduvositalen.pdfIn PDF document text
    • http://yuemeism.com/uploadfiles/files/rujajapelezewisak.pdfIn PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/c0f4425fbbc2aefa9d43f57b03e487f6/10815919168.pdfIn PDF document text
    • http://bhhangkhong.com/upload/images/files/91302541911.pdfIn PDF document text
    • https://pollackmihalyiskola.hu/ckfinder/userfiles/files/degokurerupo.pdfIn PDF document text
    • https://nusantarabet4d1.com/contents/files/bakatun.pdfIn PDF document text
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/16130de5163aab---80424132701.pdfIn PDF document text
    • https://mobspace.xyz/web/img/podborky/files/70340496803.pdfIn PDF document text
    • https://myvideoclasses.com/ci/userfiles/files/79688572316.pdfIn PDF document text
    • https://qamarapps.com/wp-content/plugins/formcraft/file-upload/server/content/files/161346155ada04---temezoredul.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_off0000d6dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6DC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eeee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEEE 16828 bytes
SHA-256: 0b575793662193b3e52a936eb481401df08881a8d23ce34590dfa5fbb630f99c
font_02_sfnt_off00011a73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A73 10764 bytes
SHA-256: 1df08a367a6da49df4c63890cafaf06e3d39690e58381e6cf7ed587ef9bbc155