Malicious PDF — malware analysis report

Static analysis result for SHA-256 640e61dc74cd3fa2…

MALICIOUS

PDF

99.3 KB Created: 2021-10-07 06:22:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: e5beb09adbd9702b9bc2dc487a000901 SHA-1: 98cd50bae21166e80f19cba51516dba123029213 SHA-256: 640e61dc74cd3fa2c975655492404b3ee77cd0730115c97e6b89efad37bf80f9
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF file that contains a link farm pointing to various PDF files hosted on potentially compromised websites. The 'SE_CLICKFIX' heuristic indicates that the document likely instructs the user to execute commands, a common social engineering tactic to bypass security measures. While no scripts were directly extracted, the presence of embedded URLs and the nature of the heuristics suggest an attempt to lure the user into downloading and executing further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9922

Heuristics 6

  • ClickFix social engineering attack high SE_CLICKFIX
    Document instructs the user to press Win+R or paste a command into a terminal — consistent with ClickFix attacks that bypass macro restrictions by tricking users into running malicious commands directly
  • 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://www.tamilsaga.com/ckfinder/userfiles/files/dilagota.pdf In PDF document text
    • https://anne-berger.de/sites/anne-berger.de/files/fkcfile/22266743564.pdfIn PDF document text
    • https://zzwgjx.com/d/files/36212888016.pdfIn PDF document text
    • https://xn--pssa17sw71b.tw/upimages/files/99802774172.pdfIn PDF document text
    • https://www.myjamaicais.com/wp-content/plugins/super-forms/uploads/php/files/0485794b39e29cea3d8d866d1e833bee/1028967796.pdfIn PDF document text
    • http://aedjtj.pretty-match.com/upload/files/23877015042.pdfIn PDF document text
    • https://badrivishal.com/media/21739138843.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161588255a1cb5---kedetedeguwunafobu.pdfIn PDF document text
    • http://akademia-jedenastka.pl/zdjecia/fck/file/zukineribiwujus.pdfIn PDF document text
    • https://gabinetpro.pl/kosmetyczka/krakow/files/78593986118.pdfIn PDF document text
    • http://stattus.com/assets/file/9493655136.pdfIn PDF document text
    • http://lnianemarzenie.pl/userfiles/file/30049577293.pdfIn PDF document text
    • https://naveenent.com/administrator/imagetemp/file/74942088418.pdfIn PDF document text
    • http://frankifoto.com/uploads/pages/files/6700438901.pdfIn PDF document text
    • http://sinching.com/uploadpic/files/202110031426216964.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615718e437fd6---60979278722.pdfIn PDF document text
    • http://exosushi.com/uploads/files/9703061381.pdfIn PDF document text
    • http://e-district.org/userfiles/file/gajeketawigadok.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/99988726045.pdfIn PDF document text
    • http://villaelen.it/userfiles/files/biwalofajoz.pdfIn PDF document text
    • http://rockhousemethod.com/ckfinder/userfiles/files/difazasomaligeboduzaguwe.pdfIn PDF document text
    • http://pakianco.ir/data/image/uploads/news/files/76606340262.pdfIn PDF document text
    • http://lunaleo.pl/userfiles/file/36420839432.pdfIn PDF document text
    • http://chemtron-vostok.ru/media/file/71283577756.pdfIn PDF document text
    • http://harlit.com/ckfinder/userfiles/files/20210906_022004.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=best+offline+english+arabic+dictionary+for+pcPDF 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_off0001187c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1187C 11208 bytes
SHA-256: 465fb13151cdbc01327b215cecb0bc4efc91bb6befb57083756ae1388cc09cab
font_01_sfnt_off00013246.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13246 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014a58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14A58 20692 bytes
SHA-256: be01a75aea9ca31c05122a1d640078672c949ae520e0b6c0dba483ec9f1e378f