Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf5df856317ee7f7…

MALICIOUS

PDF

79.4 KB Created: 2021-09-07 08:45:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 7d8fa1632a092e1877ebac055516f49f SHA-1: ac495eb5f045d3c2042c8ebeb6d38b377e3e650a SHA-256: cf5df856317ee7f75c47a09a87660a256339755587c46fad1a9b3f298366e85b
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. The heuristics indicate it functions as a link farm, with numerous URLs pointing to potentially compromised websites or disposable hosting. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ab7fbaac073---21381081148.pdf In PDF document text
    • http://twinmd.ru/userfiles/file/3866870361.pdfIn PDF document text
    • http://usairsprings.com/userfiles/file/vogilijubisom.pdfIn PDF document text
    • https://bhsbeacon.com/FCKeditor/file/45125299542.pdfIn PDF document text
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/160af9d5d58442---lepiwujoxukotuvifiwusi.pdfIn PDF document text
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606c97e7cdc5c---87173348733.pdfIn PDF document text
    • http://jointrilogy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f52927a2d6---90576930465.pdfIn PDF document text
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/qdv3mpvt52q014ef10gjr54s8o/82179600782.pdfIn PDF document text
    • http://www.donboscovizag.org/images/files/37515614113.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/160779dcd93e76---65158480089.pdfIn PDF document text
    • http://fertilityupdates.com/userfiles/files/neketog.pdfIn PDF document text
    • http://stinpo.com/ckfinder/userfiles/files/41130760508.pdfIn PDF document text
    • http://abacusnancy.com/userfiles/file/80916400767.pdfIn PDF document text
    • https://www.ediliziaindustriale.com/wp-content/plugins/formcraft/file-upload/server/content/files/160744a8237d48---6764283495.pdfIn PDF document text
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/n85v130vfabop8d7qa3sd6hrm0/41948987978.pdfIn PDF document text
    • http://ccsl.asia/files/76849884759.pdfIn PDF document text
    • https://n95america.com/wp-content/plugins/super-forms/uploads/php/files/3188614af328ef551340a3e676d7540f/15428999617.pdfIn PDF document text
    • https://pima-alarms.rs/slicice/file/8900784911.pdfIn PDF document text
    • http://quaretti.it/userfiles/files/kedanezuwigavibopof.pdfIn PDF document text
    • http://netinflux.net/userfiles/file/26656169670.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c9c1c761228---75967672031.pdfIn PDF document text
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/379n398674fpmc3ab82q13nsd4/lopibaloliv.pdfIn PDF document text
    • http://gwardiajuvenia.pl/zdjecia/fck/file/repapovanuzawuda.pdfIn PDF document text
    • http://pop-around.com/file_media/file_image/file/bebubigafoxag.pdfIn PDF document text
    • https://datawire.gr/files/files/99569666918.pdfIn PDF document text
    • http://canxetaidientu.com/images/file/59628120697.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=self+realization+fellowship+lessons+pdfPDF 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_off0000d179.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD179 17280 bytes
SHA-256: 1bbfb0e07dd6835bad0554c363730c556cfec9081e4fac93b7db6c6b22e3fee5
font_01_sfnt_off0000fe5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE5D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011674.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11674 10816 bytes
SHA-256: fa5ef3ec9439f844461d61874873d493b3c0a9e2d634c1201f5937d0e69946fe