Malicious PDF — malware analysis report

Static analysis result for SHA-256 872bc821289d2967…

MALICIOUS

PDF

82.0 KB Created: 2021-09-14 05:58:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 77bf474f784aa4e84f3b238afffc835a SHA-1: b7cbee10e388dbdc33df1969c26f1610c1ec3642 SHA-256: 872bc821289d2967d81d4d9e6c302d68d12bd51e922fe848c92e0ddc0e3cfbbc
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. The document contains numerous embedded URLs, many of which point to PDF files hosted on what appear to be compromised WordPress sites or disposable hosting. This suggests a link farm designed to lure users to malicious content, likely for phishing or SEO poisoning.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://cructi.ru/uplcv?utm_term=fire+hd+10+9th+generation+android+version PDF link annotation
    • http://racecross.com/upload/edito_fckeditor/file/7291577218.pdfIn PDF document text
    • http://mansiya.com/uploadfile/files/44020140134.pdfIn PDF document text
    • http://dijladentalcenter-qa.com/userfiles/file/jagimewari.pdfIn PDF document text
    • http://thuephotocopytaihanoi.com/upload/files/rekafena.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/8d8722fdfc969f3caed6d1aff07cead2/27608051484.pdfIn PDF document text
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fe400c964d---kuxajakaga.pdfIn PDF document text
    • https://happen.webasl.com/userfiles/file/65068633959.pdfIn PDF document text
    • http://mariekevanvlierden.nl/survey/userfiles/files/3253603427.pdfIn PDF document text
    • http://cathyknightwaite.com/ckfinder/userfiles/files/31271891651.pdfIn PDF document text
    • https://chetanaus.org/bheru/uploadfiles/file/dajigaxisufabar.pdfIn PDF document text
    • https://perfecthospitals.com/ckfinder/userfiles/files/zudasalaxibumero.pdfIn PDF document text
    • http://aftckwt.com/uploads/file/ferubofokuvas.pdfIn PDF document text
    • http://njbeihang.com/uploadfile/file///2021091314171996.pdfIn PDF document text
    • http://jolanyee.com/upload/files/202109132013086441.pdfIn PDF document text
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613a91ccb33aa---xowekavinif.pdfIn PDF document text
    • http://www.waetsukai.jp/system/ckfinder/userfiles/files/98774073332.pdfIn PDF document text
    • http://hongshengfish.com/uploadfiles/20210904/2109041605165011372z46n23sbwky.pdfIn PDF document text
    • https://iqrainternationalschool.org/_assets/files/72180758154.pdfIn PDF document text
    • https://franchisebusinessadvisors.franchisebrokerwebsites.com/broker-site/files/files/levifabufunavajidinitoxi.pdfIn PDF document text
    • https://czus-lukasa.sk/userfiles/file/3799125423.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/bf7iikk443niq9nin32v4mkl90/romoxewugib.pdfIn PDF document text
    • http://ildongwire.com/userfiles/file/livojulijukutaxo.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_off0000d8ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8AC 10868 bytes
SHA-256: 830faa2f032984248daaabfe539ae856a272c20ed1ea5d8d18ce651113092df8
font_01_sfnt_off0000f19c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF19C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000109ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109AE 18524 bytes
SHA-256: 38587aed961b3b5cd2dcea0296a9a5e36fd0fe4869d2cc881bcd0a092056d191