Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c891c8ff1ce5da6…

MALICIOUS

PDF

87.5 KB Created: 2021-08-07 11:28:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: ef2c6984cc85b308120c8427975ff711 SHA-1: dd657d2be3ab2fa455bab3e726df84dbd6ef122e SHA-256: 9c891c8ff1ce5da646ff963df1fd4decfd7281928cffe163f960142ce6378e31
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress sites, likely serving as a lure for users to download further malicious content. The presence of numerous links, many with 'utm_term' parameters suggesting SEO manipulation, reinforces the phishing pretext.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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 http://clinicacomciencia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c6adf9d1814---rokufug.pdf In PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/fmss1e36ck6qlc30mhf610trh3/73244901997.pdfIn PDF document text
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/2ee7f036a9eafce1478f7e38f97fcb4e/zizexagapogojopav.pdfIn PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/53df4hd6cjvuii5orgok3jtcmo/78700008987.pdfIn PDF document text
    • https://autotoner123.com/home/autotone/public_html/ckeditortest_WORKING/ckfinder/userfiles/files/fabilidizapix.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/17884288673.pdfIn PDF document text
    • https://eslms.com/userfiles/file/lewiwule.pdfIn PDF document text
    • https://cuichi177.com/uploads//files/202108042043435458.pdfIn PDF document text
    • http://rydelko.pl/userfiles/file/10015220216.pdfIn PDF document text
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16088d5e3459cd---jurepasomuvivezisumuki.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096462f818ca---nozulepotoletitozosu.pdfIn PDF document text
    • https://rebel-guitars.com/wp-content/plugins/super-forms/uploads/php/files/e69bae86fbf58d35035f598a05bde716/64504130135.pdfIn PDF document text
    • https://www.infrascale.com/wp-content/plugins/super-forms/uploads/php/files/655d29bd48d2bdf02b4b864448f91e58/839661781.pdfIn PDF document text
    • http://thuexedanang247.com/uploads/image/files/vamunaluxezexuzadov.pdfIn PDF document text
    • https://www.onestopnaturalstore.ca/wp-content/plugins/super-forms/uploads/php/files/gku2c119ca65m73q5c67eqkcha/83330327183.pdfIn PDF document text
    • http://bobhendrix-law.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/fasimogesafuralunezefupi.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/l9ce01vqfq3qe5o21gl6rtqao0/71095882679.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aaaeb31b719---poriturufaruvapikepo.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/6487cd9bd57de9f5e919dee6640fb154/sisedosowimeto.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/4142119073.pdfIn PDF document text
    • http://nnrhc.com/clients/9/98/980d61ede38c9a35fe3396fb65651545/File/mosake.pdfIn PDF document text
    • https://dehaventransportation.com/home/de/public_html/ckfinder/userfiles/files/53724388022.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=call+of+duty+mobile+hack+uc+apk+1.0.17PDF link annotation
    • http://lovewhereyoulv.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/8bc57a3b9e0722d1aff1045626e6785e/65388795358.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_off0000eec6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEC6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000106dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106DD 11280 bytes
SHA-256: 50f8329d795299439cca57b8caf0afc8273d04e7ecddd356e7b825daa74db109
font_02_sfnt_off00012145.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12145 17532 bytes
SHA-256: fb19aa1aa4ae1466b22a3e737a4553485f0f77f583b67019b05c3554f3d9bf8d