Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9a79cc8a21bbb15…

MALICIOUS

PDF

84.3 KB Created: 2021-09-11 21:51:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 682a3079e45031df63906bf3dd9483fa SHA-1: 012913788ea33040af9244e20dd78d96a7ff0a1b SHA-256: b9a79cc8a21bbb15391b3e95b8d4d6b3327fbc59aec48c932813434954c5ce39
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. It functions as a link farm, with numerous URLs pointing to potentially compromised WordPress sites and disposable hosting, designed to redirect users. The presence of multiple PDF link farm heuristics reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://spotiverify.com/ci/userfiles/files/bebukufigebuli.pdf In PDF document text
    • http://ecohost.ru/pics/images/file/zubugupijupalejitirepa.pdfIn PDF document text
    • https://designsdubaiukfashion.com/userfiles/file/67131643928.pdfIn PDF document text
    • http://zaintik.org/files/galeria/files/tezotokawobewo.pdfIn PDF document text
    • https://stepweystudy.com/ckfinder/userfiles/files/99626015291.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613c1e2c64117---3621479635.pdfIn PDF document text
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/a2c497a64b097f38b8e5fb3df7556a52/72782156756.pdfIn PDF document text
    • http://thebankcardservices.com/uploads/files/xodawimilefujije.pdfIn PDF document text
    • http://webs123.com/userfiles/file/68472443080.pdfIn PDF document text
    • https://mysmartedu.com/uploadimages/files/zoresitoxurudipuxi.pdfIn PDF document text
    • https://beta.nhatthiengroup.com/files/uploaded/files/75334992391.pdfIn PDF document text
    • http://peaceinsrilanka.lk/ckfinder/userfiles/files/75231052471.pdfIn PDF document text
    • http://sgd42.ru/userfiles/file/matalurijonuparakiwipora.pdfIn PDF document text
    • http://gramercy-grand.ru/files/file/38029293074.pdfIn PDF document text
    • http://zkqzl.com/uploadfile/file///2021090900473448.pdfIn PDF document text
    • https://zmiz.hr/userfiles/file/45744957311.pdfIn PDF document text
    • https://total-sport.pl/img/upload/files/pufuropopusomanegoxawu.pdfIn PDF document text
    • http://businessvaluationapp.com/fck_files/file/kozirevuzudiboz.pdfIn PDF document text
    • https://doanandieuduong295doson.vn/namthuan/images/news/files/96958236043.pdfIn PDF document text
    • https://svetplus.com/userfiles/files/fapejifevasawi.pdfIn PDF document text
    • http://jungam21.com/upfiles/file/1631082432.pdfIn PDF document text
    • http://tingchucontrol.com/Uploadfiles/files/11084845005.pdfIn PDF document text
    • https://howardsteeves.com/wp-content/plugins/super-forms/uploads/php/files/694564d29952048a03ee10e8cd8f5fdb/8688278680.pdfIn PDF document text
    • https://cmoretv.com/userfiles/wigonemagotizi.pdfIn PDF document text
    • https://subded.org/userfiles/file/71593280077.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=dolphin+browser+reviewPDF 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_off0000e526.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE526 10380 bytes
SHA-256: 371fded1f53bc89f344828ca75574a2ed6a70a0958e25c655251d1727c6a7ad2
font_01_sfnt_off0000fc4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC4F 18068 bytes
SHA-256: f586b661424c7890b81239da18b88e5214e4e511c5bd00d482c23c36e75088aa
font_02_sfnt_off00012b4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B4A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1