Malicious PDF — malware analysis report

Static analysis result for SHA-256 403fde764a4098f6…

MALICIOUS

PDF

76.5 KB Created: 2021-09-09 17:30:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 5be79ef1fb755628872e0a7eabc8e65c SHA-1: d28d4d0a6cbd2be8a58fc52283e2c3a4e62d15f5 SHA-256: 403fde764a4098f64e3e9b2cd91df95adef0bb874eafd3c3c557678262cb28d3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains numerous embedded URLs that form a link farm, with several pointing to compromised CMS upload directories. The primary purpose appears to be redirecting users through these links, potentially leading to phishing sites or further malware downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://wastran.ru/uplcv?utm_term=android+wallpaper+tumblr PDF link annotation
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/2940cc0141b7f09437365875d3223f57/zogavanaz.pdfIn PDF document text
    • https://studiecarriere.it/uploads/file/jugusujelezobusurazodi.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f789f7c0b4---76433441691.pdfIn PDF document text
    • http://mfcwestenkwartier.nl/beta/userfiles/file/xiwotibiguworugizoxu.pdfIn PDF document text
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613567bfdcc2c---69027831379.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/8tapmksfmvfq8rj2seq72adgoi/17044538437.pdfIn PDF document text
    • http://ministryofrum.com/memlogos/file/tusameweb.pdfIn PDF document text
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/7803170892.pdfIn PDF document text
    • http://claudiamelchior.it/images/file/95523821850.pdfIn PDF document text
    • http://keemunblacktea.cn/uploads/file/040132431852.pdfIn PDF document text
    • http://konberdbio.com/upload/files/87344157910.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f811abe658---xonibewugupifiwuboxobelo.pdfIn PDF document text
    • https://organicfertilizerproduction.com/d/files/1149028623.pdfIn PDF document text
    • http://xn--80ahcjevtqq.xn--p1ai/ckfinder/userfiles/files/4550956436.pdfIn PDF document text
    • http://salman-is.com/userfiles/file/52073061071.pdfIn PDF document text
    • https://highlander-inn.com/assets/userfiles/files/xefoxu.pdfIn PDF document text
    • http://vitacanes.com/uploads/files/vebedijeneveda.pdfIn PDF document text
    • http://prospekt-rostov.ru/ckfinder/userfiles/files/nojewe.pdfIn PDF document text
    • https://hobbes-group.com/upload/files/7228902734.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/3c88898921efe5781a993a88f07f7306/sesoradolivunipimogig.pdfIn PDF document text
    • https://bi-kiesabbau.de/cmsimple/images/file/80366621625.pdfIn PDF document text
    • https://khoahoc.timviec365.com/picturesfiles/suwetezup.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_off0000c973.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC973 16664 bytes
SHA-256: eb8375d73603efeb2d633b032c2e0c197055df64f79fcf1535666a16221f0a48
font_01_sfnt_off0000f439.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF439 10692 bytes
SHA-256: 150a912b55bb9598c871aa247c77e3df9368725d8a1bba164d882c6fa5b5ace2
font_02_sfnt_off00010c7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C7E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1