Malicious PDF — malware analysis report

Static analysis result for SHA-256 155f83d3b12c2cfe…

MALICIOUS

PDF

75.8 KB Created: 2021-09-04 09:37:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: b6c39395af816956019644bcc5a87c9f SHA-1: 5c68080438b26bdbb2326f22e51c76cb911c164f SHA-256: 155f83d3b12c2cfe403609eb8f43604dac6c116bb8373bfee1520f69736493d2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains numerous links to external websites, many of which are hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users. The PDF structure and embedded URLs indicate an attempt to lure users to phishing or malware-hosting sites, likely disguised as search results for specific documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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://inwebjor.ru/uplcv?utm_term=elegy+written+in+a+country+churchyard+pdf+download PDF link annotation
    • https://mides.vn/images/ckeditor/files/wasinejoginozifinezif.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a82bd108cca---17665069679.pdfIn PDF document text
    • http://dogoducthien.com/uploads/files/67910139183.pdfIn PDF document text
    • http://reszke.pl/fckeditor/editor/filemanager/connectors/php/file/85709986569.pdfIn PDF document text
    • http://aep-tc.com/cache/fck_files/file/9182348437.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/16086f726938a1---fesoxivubataguf.pdfIn PDF document text
    • http://apple888.vn/luutru/files/8965640156.pdfIn PDF document text
    • http://shanghaiqingchen.com/upload/files/vofegi.pdfIn PDF document text
    • https://lordoptika.hu/files/files/28445226620.pdfIn PDF document text
    • https://digireg.org/upload/vemorusulezafutitugetoba.pdfIn PDF document text
    • https://mama-light.net/business_school/uploads/file/kokadirikubisejini.pdfIn PDF document text
    • https://bookatowncar.com/userfiles/file/38417293010.pdfIn PDF document text
    • http://ducthoaudio.com/upload/files/zoxikobet.pdfIn PDF document text
    • http://tdbakademi.org/userfiles/files/zofamaxexozubazuxizeb.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/ipbogvrbkv81fedn1ta0s1unpe/jusirutijufufukomejugafo.pdfIn PDF document text
    • https://xn--90ah6akb9e.xn--p1ai/f/file/39314644574.pdfIn PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cb944bc8d61---buxuvomirezuga.pdfIn PDF document text
    • http://septumdent.com/img/userfiles/files/49983323592.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083d13d49ecb---jozumafapajirupipugi.pdfIn PDF document text
    • https://anfauglir.com/images/file/tusopav.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/160754836d0b9a---likejajajewonaxen.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16072e5aa683af---90806484145.pdfIn PDF document text
    • https://www.domaine-boussard-chablis.fr/ckfinder/userfiles/files/43882503230.pdfIn PDF document text
    • http://trendymamy.pl/userfiles/file/44508015457.pdfIn PDF document text
    • https://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/aa33462f1c34646d354049aa29538399/85879741152.pdfIn PDF document text
    • https://www.lightingsolutionsinc.net/wp-content/plugins/super-forms/uploads/php/files/4ee737e95e4c6d77c52b2191c4ba8d48/romow.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_off0000c414.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC414 11016 bytes
SHA-256: fc3ff217ebeaeb0129844d1ecf08a2df2ec5ad485680346f7e0076a431f30bfc
font_01_sfnt_off0000dd72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD72 16832 bytes
SHA-256: 63edde91aec5aa9add2035ad011788a7da503c87f6285f78c4c2127a5384b1e0
font_02_sfnt_off000108a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108A2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1