Malicious PDF — malware analysis report

Static analysis result for SHA-256 01668641da923316…

MALICIOUS

PDF

85.8 KB Created: 2021-09-14 10:01:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 9918b5a9914d0ba60e547d3b4b75d2d3 SHA-1: 6bb0a400ed58da2cc2bfc1bc8870e306f22a52c9 SHA-256: 01668641da92331626504ab6868f6751ac9f3b31c91aa2d577148e84fad9290d
156 Risk Score

Malware Insights

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

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 numerous domains, some of which appear to be compromised WordPress uploads. The presence of multiple external URIs and the nature of the heuristics suggest the document is designed to redirect users to potentially harmful websites, likely for phishing or malware delivery.

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://krisoc.ru/uplcv?utm_term=how+to+pair+two+android+phones PDF link annotation
    • https://gemwares.com/userfiles/file/sisavufewipujabeveg.pdfIn PDF document text
    • http://jimsclub.net/new/board/img_tinfo/file/20210910153503.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/c3d8ba1bf73a8bcc1e7b1c282517ff13/20888649857.pdfIn PDF document text
    • https://haruhonpo.com/upload/haruhonpo/files/51344197342.pdfIn PDF document text
    • http://eastcity.hu/ufiles/file/595741995.pdfIn PDF document text
    • http://www.c-l-r-p.com/admin/ckfinder/userfiles/files/26583513793.pdfIn PDF document text
    • http://holland-ex.com/images/blog/file/suwofenatevu.pdfIn PDF document text
    • http://tivatijapan.com/uploads/userfiles/file/32167075973.pdfIn PDF document text
    • http://manvilastrust-org.bvirani.com/ckfinder/userfiles/files/tapuzab.pdfIn PDF document text
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/fd129485df85f591714ea5ead76b7f82/85397064281.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f22fe2666b---sixunivewijejezo.pdfIn PDF document text
    • https://allcondosales.rodeodrivecondosale.com/userfiles/files/maxasiperux.pdfIn PDF document text
    • http://szerecsengyogyszertar.hu/editor_up/rikuziv.pdfIn PDF document text
    • http://lagostena.it/userfiles/files/23585321212.pdfIn PDF document text
    • http://azco.friend-match.com/upload/files/72873090447.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/161398c4fd6c4f---moworatubekuvomuwepagowiz.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/161401904287d0---tezemunelofalime.pdfIn PDF document text
    • http://homeopathyhongkong.cn/files/namejiruzebawini.pdfIn PDF document text
    • http://aromata.ru/upload/files/rulenamogomadez.pdfIn PDF document text
    • https://12waktu.com/contents/files/64540834448.pdfIn PDF document text
    • https://highlander-inn.com/assets/userfiles/files/paxikojafewiwaxavulepo.pdfIn PDF document text
    • http://srividyaastrology.com/userfiles/file/65912876819.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613d9cd60ff60---27245829511.pdfIn PDF document text
    • https://limsurdua.com/contents/files/82622021488.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_off0000eb2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB2B 17620 bytes
SHA-256: ae0390fb162b0c0501235fc31f0dd095600c84b81ecfb4fdc2cd71069eedbd06
font_01_sfnt_off00011943.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11943 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001315a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1315A 10520 bytes
SHA-256: 1796655624be6d91d389758fab002ce215cb3229c2f27e4524b896af2d8d214b