Malicious PDF — malware analysis report

Static analysis result for SHA-256 3bbfdfd5887b227e…

MALICIOUS

PDF

86.0 KB Created: 2021-09-17 18:28:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4a376297c2c53bc82297d66ac7f0da9c SHA-1: 5480c82757ea754bc93a0ef37b03d3cc9760a965 SHA-256: 3bbfdfd5887b227e2c5273384d984a14be41363565f0f131f34a81bc43aad096
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to external PDF files. Many of these URLs are hosted on domains that appear to be compromised or disposable, suggesting a tactic to distribute malicious content or engage in SEO poisoning.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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 https://vaynhanh365.net/contents/files/46911380902.pdf
    • http://china-baby-clothes.com/d/files/nonulijimodalo.pdf
    • http://dealershop.es/userfiles/file/23863552319.pdf
    • http://chpcentre.com/files/file/5506379984.pdf
    • http://noithatdangcap.vn/app/webroot/uploads/files/wokosojegavago.pdf
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/pgcp896jd168c6oo5k84jabhf0/fozixipagadoju.pdf
    • http://biomehl.com/images/content/files/5662950483.pdf
    • https://farmaciasacoor.com/site/upload/file/68212311713.pdf
    • http://asfalon.com/__files/file/bojizabapikusi.pdf
    • http://www.findvoters.com/userfiles/file/84331964011.pdf
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/bbdf4f8133be76d6a6ac2170d9111df8/72198984171.pdf
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/d2bg49ctt2gv2pq2dlpkud7510/biwajanigi.pdf
    • http://bibliotekaludwin.pl/img/upload/files/97247447750.pdf
    • http://xn--90afqerdlt1f.xn--p1ai/admin/ckfinder/userfiles/files/66646716966.pdf
    • http://maketmaster.ru/admin/ckfinder/userfiles/files/reramexufukanubufefin.pdf
    • http://vin-baietii.ro/ckfinder/userfiles/files/9256588200.pdf
    • http://kor-ra.ru/UserFiles/file/zidufuwetusudiz.pdf
    • https://futurefacesmiami.com/uploads/file/24991314809.pdf
    • http://abwrichmond.com/uploads/files/76861393012.pdf
    • http://dalaichau.com/files/nesemoxilagaj.pdf
    • http://sonsuadogo.org/Images_upload/files/50958437998.pdf
    • https://atavio.ru/files/file/kenujeke.pdf
    • http://rpsbchamber.org/editorData/file/10837177396.pdf
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/161380d520b992---pipefudulesewosexafe.pdf
    • http://klpa.net/userData/board/file/45592919483.pdf
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/pgc25dtvucm4ea4qr5c1sonrkk/xofomosoxezatiwizuba.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=oceanhorn+apk+full
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e7f0.bin
1c13afb4589ceec5f44695f866793b306c3beaabcf1901504256e4cfff5fa864
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7F0 19444 bytes
font_01_sfnt_off00011a52.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A52 16792 bytes
font_02_sfnt_off00013269.bin
c6f876f88032c89c95c6ea90410db7b3e224188dd06f0705d1b9e0e30ff20622
pdf-font-stream PDF embedded font (sfnt) at offset 0x13269 10436 bytes