Malicious PDF — malware analysis report

Static analysis result for SHA-256 c78a533d864ff302…

MALICIOUS

PDF

79.7 KB Created: 2021-09-16 07:56:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 05b724210f2a18ae5c2e349798a796b4 SHA-1: 7f561f4b81f0b8be34d4896c7fc6d30eed7d0e83 SHA-256: c78a533d864ff30297ad256141336e7e82567d4ca368cab094cf6b4c1917f5a3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains a link farm pointing to multiple domains, including compromised WordPress sites and disposable hosting, suggesting an attempt to redirect users to malicious content or phishing pages. The PDF structure and embedded URLs indicate a phishing or malware distribution lure, likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://inwebjor.ru/uplcv?utm_term=candy+crush+saga+crack PDF link annotation
    • https://studybrilliant.online/app/webroot/img/userfiles/file/30620767013.pdfIn PDF document text
    • http://autothudo.vn/upload/fck/file/zesumo.pdfIn PDF document text
    • https://cristiandellavedova.com/wp-content/plugins/super-forms/uploads/php/files/b56bc80c88ddc28ac4743087a69afc74/51398425948.pdfIn PDF document text
    • http://mitsubishilongbien.vn/images/ckeditor/files/2572748089.pdfIn PDF document text
    • https://rinducm1.com/contents/files/48407731473.pdfIn PDF document text
    • http://energosol.pl/images_cms/file/gavopowojorodeloz.pdfIn PDF document text
    • http://medi-sen.com/files/files/32460171363.pdfIn PDF document text
    • https://bangvetthuong.com/luutru/files/jebemebomunu.pdfIn PDF document text
    • http://trungnguyenjsc.vn/uploads/image/files/falebuzakujogipexip.pdfIn PDF document text
    • http://handgun.ee/media/file/babovotuzeva.pdfIn PDF document text
    • http://form4concrete.ru/pics/cont/file/1722175500.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613babb98ab16---44795300396.pdfIn PDF document text
    • http://millionsdiscount.com/mo_images/files/sekaku.pdfIn PDF document text
    • http://greenglobepms.com/uploads/84724742217.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135510e95eb2---33310623105.pdfIn PDF document text
    • https://bczenekar.hu/files/file/kifigodi.pdfIn PDF document text
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/samujekesisepesanakutor.pdfIn PDF document text
    • http://humanitool.ru/userfiles/file/sizitasusurazedumak.pdfIn PDF document text
    • http://thegioimercedes.com/upload/files/8716526611.pdfIn PDF document text
    • https://tonmathunglan.vn/upload/files/96379970751.pdfIn PDF document text
    • https://gfwofficial.com/ck_imgs/files/lelerovulazi.pdfIn PDF document text
    • https://fedico.ca/upload/editor/file/rewuruwiriba.pdfIn PDF document text
    • http://myphamlulanjina.com/upload/files/31870306099.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_off0000d4cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4CD 17384 bytes
SHA-256: 7593a250c81e124a04847e60abad6eafd859751c2e965837e66cae3c6e20c8f5
font_01_sfnt_off000101b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101B9 10500 bytes
SHA-256: e3bc80896108267656c0ef914902e2057dd7c6a610478c57862711c67b4ec258
font_02_sfnt_off0001195b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1195B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1