Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5b0fff88dcb65bd…

MALICIOUS

PDF

72.6 KB Created: 2021-09-01 17:08:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 33d292677920193b43a678bec058e758 SHA-1: f182c4712c91c50efbcb5af820605cc89f8daf56 SHA-256: a5b0fff88dcb65bda0954a0a25e9328523df283547849f4efb26039856dd24c6
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised WordPress sites, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. The document body is heavily obfuscated and does not provide direct clues to the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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://uclerbaklava.com/resources/file/19741822646.pdf
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/62c700b11a441f22c3f0fd7f9c87f8ef/48185572874.pdf
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608466dc53ad7---dijigamutomorutifavuf.pdf
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/1c8bb5eb52b39bb48e48ffefab16ba72/fevovabe.pdf
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/37d194dcd60d74be5aedc86a40900ed7/56330847066.pdf
    • http://terremeraude.com/userfiles/file/koxoru.pdf
    • https://dursunguney.com/userfiles/files/40726113229.pdf
    • http://alnoorcity.com/userfiles/file/81216836105.pdf
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d80e3295395---47502921404.pdf
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7abe9ef51---20395601869.pdf
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16078c5263e98d---gisamapavidiruwexupezow.pdf
    • http://sbkf.org/files/files/7835678576.pdf
    • https://www.sehersirin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e986252f06---lufofutixux.pdf
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/160ee27d23f1c0---72400184773.pdf
    • http://chia4kids.ru/ckfinder/userfiles/files/semep.pdf
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/tl72pjarknf4u1cctfrqsfhgq1/62763997774.pdf
    • https://fnb-concepts.com/images/uploads/files/fetejosiwopawejosonezuj.pdf
    • https://prawobrzeze.info/userfiles/file/23132583635.pdf
    • https://stiff.pl/ckfinder/userfiles/files/90331497317.pdf
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/buvixa.pdf
    • http://mezon.jp/userfiles/file/30584823413.pdf
    • https://ivanda-commerce.hr/userfiles/file/74678888219.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=mother%27s+day+kavithai
    • https://lapdonline.org/file/79556830181.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bcf5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBCF5 16792 bytes
font_01_sfnt_off0000d50c.bin
a15aaab06f50d1fdb394bb8fe1d0623f1438db7c59161dba9df592387ffbbdeb
pdf-font-stream PDF embedded font (sfnt) at offset 0xD50C 10496 bytes
font_02_sfnt_off0000ed34.bin
e4614e32c0c2e521d3a21b7ead1a169daed4436206cd49ebc8f58512f9f87221
pdf-font-stream PDF embedded font (sfnt) at offset 0xED34 15508 bytes