Malicious PDF — malware analysis report

Static analysis result for SHA-256 158d98875b1bcbbe…

MALICIOUS

PDF

99.0 KB Created: 2021-07-07 17:58:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 96e0a806a841037e8f6f019607592e4d SHA-1: aab557642af0910c856d67e441715eb677dc66b5 SHA-256: 158d98875b1bcbbea077279f0c859dd162386352b3871950548cfad1b9078bc5
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple domains, some of which are hosted on compromised CMS uploads. The embedded URLs, such as http://reversetheclocknow.com/ckfinder/userfiles/files/85610395283.pdf, are likely used to distribute further malicious content or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9895

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://reversetheclocknow.com/ckfinder/userfiles/files/85610395283.pdf In PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/ap159iidbrn3upnqkm992t10q3/mowijefudadotojafes.pdfIn PDF document text
    • http://transbur.ru/admin/ckfinder/userfiles/files/kesutopavoteniduzegiba.pdfIn PDF document text
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dbf0f53aef1---juludunexejidufaxejegekun.pdfIn PDF document text
    • http://springhs1988.com/clients/a/a7/a70db2535ed58991dd9724faf9b165d0/File/domonisu.pdfIn PDF document text
    • http://zbraneklapka.cz/ckfinder/userfiles/files/gaduwokabagugefib.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/eofo51iai298sb97h3hg68r2s2/vajesote.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607030d5d3de3---70947264823.pdfIn PDF document text
    • http://ateliergermain.net/sites/default/files/file/16167193720.pdfIn PDF document text
    • http://apvn.info/userfiles/file/belub.pdfIn PDF document text
    • https://novamakine.com/upload/ckfinder/files/874713096.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/d1b3e422f402ed80c6f38a0dbe954d0c/85640978249.pdfIn PDF document text
    • https://thegioidongphuc.net/ckfinder/userfiles/files/linesajizanudasoranis.pdfIn PDF document text
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/d95f540739ad25c84694905cfc8b6600/62575696677.pdfIn PDF document text
    • https://movesforfree.com/wp-content/plugins/super-forms/uploads/php/files/j46370clcrv6rakp4176ci1je5/22501267637.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160d62d7309f26---fupirukuwixow.pdfIn PDF document text
    • https://cortemadera.com/wysiwygfiles/file/nujagipugepiragirebuga.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/5dffe1b135ddd904eb5f6cd6c22d8769/kokumupexib.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/160af95e55aa97---52476827307.pdfIn PDF document text
    • http://arqing.es/ckfinder/userfiles/files/12703670852.pdfIn PDF document text
    • https://xn--hjrnskadeakademien-mtb.se/userfiles/file/gukuvoxurufa.pdfIn PDF document text
    • http://qhzs88.com/admin/fckeditor_upfiles/file/2021070705174280554.pdfIn PDF document text
    • http://mazdooradda.com/userfiles/file/98689665084.pdfIn PDF document text
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/160873f3387861---36770673334.pdfIn PDF document text
    • http://ash-graphy.com/userfiles/file/lalonodatagajafe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=fall+in+love+at+first+kiss+download+eng+subPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010b9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B9E 10992 bytes
SHA-256: 3b21e8379db1df04311771054598fd3217b05ba38f3c4593f52a865a154e47dd
font_01_sfnt_off00012519.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12519 23388 bytes
SHA-256: db1aea8c7f8763802ffb44f8d4c0e54a9c6e4e9b5acf1b1674a2b0be393802ad
font_02_sfnt_off00015b0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15B0C 2572 bytes
SHA-256: 80df2d8e12d88a75dfcf2817cf06b6438de3827e02c630877fa4ba393464f582
font_03_sfnt_off000165e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x165E6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1